Merge pull request 'Features/page numbers' (#4) from features/page-numbers into develop

Reviewed-on: #4

agents.md

@@ -38,7 +38,7 @@ pnpm build               # Create the adapter-node production build
 pnpm preview             # Preview the production build
 pnpm check               # Run Svelte and TypeScript diagnostics
 pnpm check:watch         # Run diagnostics in watch mode
-pnpm test:e2e            # Run the Playwright toolbox tests in Chromium
+pnpm test:e2e            # Run the toolbox specs (tests/e2e) and the unit specs (tests/unit)
 pnpm test:pwa            # PWA offline/update tests against the production build (requires pnpm build)
 pnpm lint                # Check repository formatting with Prettier
 pnpm format              # Format the repository with Prettier
@@ -74,9 +74,13 @@ src/
 │   │   ├── BatchFileList.svelte          # Shared batch rows: status chips, downloads, retry
 │   │   ├── BeaArchiveProcessing.svelte
 │   │   ├── BeaWorkspaceControls.svelte   # beA workspace toolbar, settings popover, dialogs
+│   │   ├── ExhibitFileList.svelte        # Reorderable Anlagen list: labels, renames, results
 │   │   ├── ProcessedZipArchiveEditor.svelte
+│   │   ├── PaginationPreview.svelte      # Rendered page preview incl. shrink hints and page nav
 │   │   ├── PdfSplitDialog.svelte         # Page-level PDF splitting into Teildokumente
+│   │   ├── SinglePdfTool.svelte          # Shell for one-PDF tools (header, dropzone, slots)
 │   │   ├── SubDocumentEditor.svelte
+│   │   ├── ToolError.svelte              # Shared error banner (role="alert")
 │   │   ├── FileDropzone.svelte           # Shared PDF/image/ZIP file picker and drop target
 │   │   ├── ZipFilePicker.svelte          # Compact ZIP picker button with hidden resettable input
 │   │   ├── PdfPageGrid.svelte            # Accessible PDF thumbnail selection grid
@@ -89,11 +93,19 @@ src/
 │   │   ├── xml-reading.service.ts        # Namespace-tolerant XJustiz parsing
 │   │   └── zip-inflating.service.ts      # Async fflate wrapper
 │   ├── batch.ts                          # Sequential batch engine for multi-file tools
+│   ├── download.ts                       # Blob/download helpers (pdfBytesToBlob, downloadBlobFile)
+│   ├── exhibit-naming.ts                 # Anlagen label, start number and file-name helpers
+│   ├── latest-task.ts                    # "Only the latest async call wins" tokens
 │   ├── pdf-compression.ts                # Shared compression presets and rasterize pipeline
+│   ├── pdf-errors.ts                     # Shared PDF error classification and German messages
 │   ├── pdf-metadata.ts                   # PDF metadata inspection and cleaning (pdf-lib only)
-│   ├── pdf-overlay.ts                    # Shared PDF overlay positions and color parsing
+│   ├── pdf-overlay.ts                    # Shared overlay positions, preview CSS and color parsing
+│   ├── pdf-pagination.ts                 # Sheet-number labels and the pagination pipeline
+│   ├── pdf-preview-text.ts               # Canvas text measurement for HTML previews
 │   ├── pdf-processing.ts                 # Reusable PDF merge helper
-│   ├── pdf-thumbnails.ts                 # Managed pdfjs thumbnail loading and cleanup
+│   ├── pdf-session.svelte.ts             # Shared single-PDF lifecycle (file, bytes, handle, errors)
+│   ├── pdf-text-overlay.ts               # Shared framed/rotated text and image overlay drawing
+│   ├── pdf-thumbnails.ts                 # Managed pdfjs thumbnails, on-demand page previews, cleanup
 │   ├── utils.ts                          # cn() and shared component utility types
 │   └── zip-processing.ts                 # Archive model, transforms, and PDF export
 └── routes/
@@ -104,13 +116,15 @@ src/
     ├── tools/
     │   ├── +layout.svelte                # Shared back-navigation shell
     │   ├── bea/+page.svelte              # Existing ZIP archive workflow
-    │   └── {merge,separate,stamp,watermark,encrypt,decrypt,compress,convert,rotate,metadata}/
+    │   └── {exhibits,pagination,merge,separate,stamp,watermark,encrypt,decrypt,compress,convert,rotate,metadata}/
     ├── datenschutz/+page.svelte          # Privacy policy
     └── impressum/+page.svelte            # Imprint
 static/                                   # Public logo, footer art, PWA icons, and robots.txt
 components.json                           # shadcn-svelte registry configuration
 Dockerfile                                # Node adapter production image
 playwright.pwa.config.ts                  # Playwright config for `pnpm test:pwa`
+tests/e2e/                                # Playwright toolbox specs
+tests/unit/                               # Pure-function specs (run by the same Playwright config)
 plan/                                     # Design and implementation notes
 ```
 
@@ -146,7 +160,20 @@ committed.
 ## Application flow and state
 
 - `/` is the toolbox hub. A beA ZIP or PDF dropped anywhere on that route is queued in memory and
-  forwarded to `/tools/bea`; the file is not uploaded or persisted.
+  forwarded to `/tools/bea`; the file is not uploaded or persisted. The same `queuePendingFiles` /
+  `takePendingFiles` handoff carries the merged PDF from `/tools/merge` to `/tools/pagination`.
+- `/tools/pagination` is a single-PDF tool: it renders one page at a time through
+  `loadPdfPageRenderer` (never the all-pages thumbnail array), composes every label with
+  `buildPaginationLabel` — the single source for both the live preview and the export — and stamps
+  all pages through `drawTextOverlay`. The page number is always on every page; the optional free
+  text (Aktenzeichen) follows its own “every page” / “first page only” scope.
+- `/tools/exhibits` is the Anlagen tool and the only batch tool with an order. One dropped PDF is
+  one Anlage: `src/lib/exhibit-naming.ts` owns the label (`buildExhibitLabel`, no padded numbers in
+  the stamp) and the optional file name (`buildExhibitFileName`, `{prefixSlug}_{paddedNumber}_…`,
+  padding from `getExhibitNumberWidth`). Numbers are frozen per row when the run starts
+  (`assignments` map), so reordering or changing the start number never rewrites a created Anlage —
+  the list keeps showing the frozen label while pending rows follow the live order. The stamp is
+  `drawTextOverlay` with `framed: true`, `compensatePageRotation: true`, first page by default.
 - `/tools/metadata` is a single-PDF inspection tool. `src/lib/pdf-metadata.ts` reads document
   properties with pdf-lib only (no rasterization), returns a discriminated `{ status: 'encrypted' }`
   result for password-protected files, and detects embedded-file markers by scanning raw bytes.
@@ -231,6 +258,35 @@ All case-file processing is intentionally local to the browser.
 - Page-set copies (separate/extract tools, PDF splitting) share
   `copyPagesToNewPdf(sourceBytes, pageIndexes)` in `src/lib/pdf-processing.ts` so the copy
   semantics cannot drift apart.
+- `src/lib/pdf-text-overlay.ts` owns text fitting, the rotated-box placement and the optional
+  `/Rotate` compensation. Stamp keeps `compensatePageRotation` off so its output does not change;
+  pagination turns it on so numbers stay at the visual position on rotated scans. `drawImageOverlay`
+  is the image counterpart. Share both instead of re-implementing overlay maths in a route, and take
+  the margin/padding presets (`TEXT_OVERLAY_MARGIN`, `TEXT_OVERLAY_PADDING`,
+  `MIN_TEXT_OVERLAY_SIZE`) from the module rather than redefining them locally.
+- `src/lib/pdf-errors.ts` classifies PDF failures (`classifyPdfError`, `TextOverlayError`,
+  `isEncryptedPdfError`) and owns the German copy (`pdfLoadErrorMessage`, `pdfProcessingErrorMessage`,
+  both with a tool-specific fallback). All tools use it; never match on pdf-lib/pdfjs error text in a
+  route, and never copy the password hint locally.
+- `src/lib/pdf-session.svelte.ts` (`createPdfSession`) is the shared single-PDF lifecycle for rotate,
+  separate and pagination: it reads the bytes once, builds the tool handle, maps load errors and
+  invalidates stale loads. Keep new single-PDF tools on it instead of re-declaring
+  `file`/`bytes`/`handle`/`isLoading`/`loadingError` and a generation counter.
+- `src/lib/latest-task.ts` (`createLatestToken`) is the guard for "only the newest async call may
+  publish its result" (file loads, preview renders). Do not add another hand-rolled counter.
+- Markup is shared the same way: `ToolError.svelte` owns the red `role="alert"` banner (never
+  inline the classes in a route), `SinglePdfTool.svelte` owns the header + dropzone + toolbar +
+  footer layout for one-PDF tools (rotate, separate — keep new ones on it), and
+  `PaginationPreview.svelte` owns the page preview with its shrink hints. Tool-specific copy is
+  passed in as props; keep it out of the shared components.
+- `src/lib/pending-files.ts` hands files between routes. Queue with an explicit target
+  (`queuePendingFiles(files, 'bea' | 'pagination')`) and consume with `takePendingFiles(target)` so a
+  tool cannot silently swallow a file queued for another one.
+- `src/lib/pdf-thumbnails.ts` offers two loaders: `loadPdfDocument` (all thumbnails, for pickers and
+  page grids) and `loadPdfPageRenderer` (one page at a time, for long documents). Both share
+  `PdfPageImage` and one rendering helper, revoke object URLs and tear down the pdfjs loading task —
+  including when the initial `getDocument` promise rejects. Superseded renders throw
+  `PreviewRenderCancelledError`, which callers swallow instead of logging.
 - `AttachmentPreview.svelte` dynamically loads pdfjs-dist in `onMount`, copies PDF bytes before
   rendering, and revokes object URLs during cleanup. Preserve those memory and data-integrity
   safeguards.
@@ -243,16 +299,23 @@ called in the browser.
 
 ## Batch processing pattern for single-PDF tools
 
-Tools that transform one PDF per run (compress, watermark, encrypt, …) are being retrofitted to
+Tools that transform one PDF per run (compress, watermark, stamp, encrypt, decrypt) accept multiple
-accept multiple files. Follow the established compress retrofit when adding the pattern to another
+files. Follow the established compress retrofit when adding the pattern to another tool; see
-tool; see `plan/batch-processing-plan.md` for the full design.
+`plan/done/batch-processing-plan.md` for the full design.
 
 - `src/lib/batch.ts` owns the engine: `createBatchItem(file)`, `runBatch(items, process, update,
-options?)` and `formatBytes`. `runBatch` processes strictly sequentially (one PDF in flight for
+options?)`, `formatBytes`, `batchStatusLabel`/`batchStatusClass` and
-  memory safety), never throws — per-item failures are caught and written to the item as a German
+  `shouldWarnAboutBatchMemory`. `process` is `(file, item) => Promise<{ bytes, name }>`: the item is
-  error message — and consults the optional `shouldProcess` predicate so rows removed mid-run are
+  passed so a tool can resolve per-row data frozen at run start (the Anlagen tool resolves its
+  exhibit number that way; `(file) => …` callbacks stay valid). `runBatch` processes strictly
+  sequentially (one PDF in flight for memory safety), never throws — per-item failures are caught
+  and written to the item as a German error message (a string, or a formatter that can inspect the
+  thrown error) — and consults the optional `shouldProcess` predicate so rows removed mid-run are
   skipped.
-- `src/lib/components/BatchFileList.svelte` renders the rows: name, size, status chip
+- `src/lib/batch.ts` also owns the bulk export: `uniqueEntryName` (duplicate suffixes) and
+  `downloadBatchZip(items, zipBaseName)` → `{toolname}_{date}.zip`. Keep new batch tools on it
+  instead of building ZIPs inside a component.
+- `src/lib/components/BatchFileList.svelte` renders the rows: name, size, status chip (`batchStatusClass`/`batchStatusLabel`)
   (Wartet / Verarbeite… / Fertig ✓ / Fehler), per-row download, remove, and retry buttons with
   accessible names including the file name, a progress line (“Datei 3 von 7 wird verarbeitet…”), a
   total result-size summary, a memory warning (>20 files or any file >25 MB), and the bulk
@@ -262,10 +325,17 @@ options?)` and `formatBytes`. `runBatch` processes strictly sequentially (one PD
   deduplicate by name + size), pass a `process(file)` callback that reads the current option state
   so option changes mid-run affect only subsequent files, and gate the run button on pending items.
   Files too large to rasterize (>100 MB) are marked as error rows immediately on selection instead
-  of blocking the batch.
+  of blocking the batch. Keep thumbnails, previews, and page-specific selection to a single dropped
-- Per-tool ZIP base names: compress uses `komprimiert`, watermark `wasserzeichen`, encrypt
+  file; multi-file runs apply the tool to every page of every file.
-  `geschuetzt`, decrypt `entsperrt`. Choose an analogous German name per tool and cover the batch
+- `src/lib/components/ExhibitFileList.svelte` is the other batch list, for tools where order and a
-  flow with Playwright tests (multi-file ZIP contents, failure continuation, retry, removal).
+  derived per-row label matter (currently `/tools/exhibits`): drag handle plus up/down buttons that
+  both call one `onMove(from, to)`, position badge, the resolved label, the renamed file name, and
+  the same status/download/retry/remove/ZIP surface as `BatchFileList`. Reordering and preview
+  selection are disabled while a run is active.
+- Per-tool ZIP base names: compress uses `komprimiert`, watermark `wasserzeichen`, stamp `stempel`,
+  exhibits `anlagen`, encrypt `geschuetzt`, decrypt `entsperrt`. Choose an analogous German name
+  per tool and cover the
+  batch flow with Playwright tests (multi-file ZIP contents, failure continuation, retry, removal).
 
 ## Svelte conventions
 

plan/done/exhibit-numbering-plan.md

@@ -0,0 +1,237 @@
+# Plan: Anlagen-Bezeichnung — Anlagen nummerieren und benennen
+
+## Goal
+
+Add a new tool **„Anlagen nummerieren“** (`/tools/exhibits`): users drop any number of PDFs, sort
+them, choose an exhibit label („Anlage“, „Anlage K“, „Anlage B“, „Anlage XYZ“ or free text), a start
+number and the page scope, and receive each PDF stamped with its exhibit number — optionally renamed
+to `Anlage_K_06_Originalname.pdf` for court submission.
+
+Context: mail thread with Nikolai Klute (26.09.2026 / 06.10.2026). The requirement is explicitly
+_one PDF = one Anlage = one number_, with sortable order, configurable label and counter start, and
+optional filename prefixing. Per-page counters are the separate pagination plan.
+
+Related: `plan/done/page-numbers-plan.md` (shared overlay/renderer), `plan/done/stamp-plan.md`,
+`plan/done/batch-processing-plan.md`.
+
+---
+
+## Open decisions (defaults marked ✅)
+
+### D1 — Numbering unit
+
+- ✅ **A. One uploaded PDF = one Anlage = one number.** An „Anlage K 6“ may have many pages; the
+  stamp identifies the document, not the sheet.
+- B. Group several PDFs into one Anlage. Not requested; deferred (a group would need its own reorder
+  UI inside a group).
+
+### D2 — Stamped pages
+
+- ✅ **A. First page by default,** checkbox „Auf jeder Seite stempeln“ for every page of that
+  exhibit.
+- B. Every page by default. Real exhibit stamps usually mark the first page; the stamp tool already
+  covers „everywhere“.
+
+### D3 — Look
+
+- ✅ **A. Framed exhibit stamp:** `Anlage K 6` in title case, HelveticaBold 14 pt (slider 10–24),
+  black `#1a1a1a` (color input included, same control as the stamp tool), 2 pt border, 6 pt padding,
+  no rotation, no date, default position **oben rechts**, 20 pt margin; the six other positions are
+  selectable.
+- B. Reuse the red authority stamp look. Wrong signal: an exhibit label is a designation, not an
+  endorsement.
+
+### D4 — Label and presets
+
+- ✅ **A. Preset chips + editable text.** Chips `Anlage`, `Anlage K`, `Anlage B`, `Anlage XYZ`
+  (`maxlength="40"`, default `Anlage`). The stamp text is `${prefix} ${number}` with a single space —
+  no leading zeros in the stamp (`Anlage K 6`, not `Anlage K 06`).
+- B. Fixed list only. Firms use their own exhibit letters.
+
+### D5 — Filename renaming
+
+- ✅ **A. Optional, default on.** Pattern `{prefixSlug}_{paddedNumber}_{originalBase}.pdf`, e.g.
+  `Anlage_K_06_Klageschrift.pdf`. Prefix slug: trim, collapse whitespace to `_`, strip
+  `/\:*?"<>|` and control characters, keep German letters. Padding = `max(2, digits of highest
+assigned number)`, so 1…99 → `06`, 1…100 → `006`.
+  Renaming off keeps the original file name exactly (ZIP duplicate names are still deduplicated by
+  the batch ZIP helper).
+- B. Always rename. Users sometimes want to control file names themselves.
+
+### D6 — Ordering
+
+- ✅ **A. Drag-and-drop with a visible handle, plus up/down buttons.** Buttons are the keyboard and
+  Playwright path; both call the same `moveItem(from, to)`. Reordering is disabled while a run is
+  active.
+- B. Up/down only. Too slow for 30 exhibits.
+
+### D7 — Number freezing
+
+- ✅ **A. Numbers are frozen when a run starts** (`itemId → start + index`). Results keep the number
+  they were stamped with even if the user reorders afterwards; the list shows
+  „Bereits erstellte Anlagen behalten ihre Nummer.“ Retry uses the frozen number. A clean renumber
+  means removing results and running again.
+- B. Live renumbering after processing. Would silently invalidate downloaded files and produce
+  duplicate numbers.
+
+### D8 — Deliverables
+
+- ✅ **A. Per-row downloads + one ZIP „Alle herunterladen“** via the existing batch ZIP engine
+  (`anlagen_2026-10-06.zip`). A merged „Anlagenkonvolut“ stays out of scope — „PDFs zusammenfügen“
+  exists.
+- B. Always one merged PDF. Not requested and destroys per-exhibit files.
+
+### D9 — Preview
+
+- ✅ **A. Preview only for the selected row**, page 1 rendered on demand (shared
+  `loadPdfPageRenderer` from the pagination plan), overlay scaled like the stamp preview; selecting
+  another row disposes the previous handle.
+- B. Thumbnail per row. Renders every dropped PDF completely — memory trap.
+
+---
+
+## UX
+
+Route `/tools/exhibits`, title „Anlagen nummerieren“, registry entry next to `stamp`:
+
+```ts
+{
+	slug: 'exhibits',
+	title: 'Anlagen nummerieren',
+	description: 'Nummerieren und benennen Sie Anlagen für die Einreichung — mit Anlagenstempel.',
+	icon: 'files'
+}
+```
+
+- **Header/description:** „Versehen Sie mehrere PDFs mit fortlaufenden Anlagen-Bezeichnungen und
+  benennen Sie die Dateien passend um.“
+- **FileDropzone** (multiple) — „PDFs als Anlagen hinzufügen“; appending keeps the current list
+  (same dedupe by name + size as the stamp tool).
+- **Numbered list** (`ExhibitFileList.svelte`, not `BatchFileList` — it needs reordering and number
+  labels):
+  - per row: drag handle, order badge, computed label („Anlage K 6“), file name, renamed preview
+    (`→ Anlage_K_06_Klageschrift.pdf`), status chip, per-row download / retry / remove, and a
+    „Vorschau“ selection.
+  - live label updates for pending rows when order, prefix or start number changes; done rows show
+    the frozen label.
+- **Options card**
+  - Bezeichnung: preset chips + text input (`maxlength="40"`), live example „Anlage K 6“.
+  - Startnummer (number input, default 1, min 0) + hint „3 Dateien → Anlage K 6, 7, 8“.
+  - „Auf jeder Seite stempeln“ checkbox (default off).
+  - Position (default oben rechts), Schriftgröße slider 10–24 (default 14), Farbe (default
+    `#1a1a1a`).
+  - „Dateien umbenennen“ checkbox (default on) with the filename pattern as helper text.
+- **Preview card:** selected row, page 1, overlay of the row's label at the chosen position; page
+  count of the selected file shown (requires loading it — the renderer reports both).
+- **Primary action** „Anlagen erstellen“ → `runBatch` over all pending rows; then per-row downloads
+  and the ZIP action. While running: „Datei 3 von 7 wird verarbeitet…“ (batch pattern) and
+  reordering disabled.
+- Errors: encrypted PDFs become per-row error rows with the shared decryption hint; an empty prefix
+  blocks the run with a German validation hint; too-long labels use the overlay's fit/error path.
+
+## Technical approach
+
+### Shared overlay and errors
+
+- Uses `drawTextOverlay` from `src/lib/pdf-text-overlay.ts` (introduced by
+  `plan/done/page-numbers-plan.md`) with `framed: true`, bold font, `compensatePageRotation: true`.
+- Uses `src/lib/pdf-errors.ts` for the encrypted-PDF message.
+- If the exhibit plan ships first, it creates both modules and the pagination plan reuses them.
+
+### Batch engine
+
+- Extend `runBatch`'s callback to `(file: File, item: BatchItem) => Promise<BatchProcessResult>` so
+  the tool can resolve the frozen number per row (existing `(file) => …` callbacks remain valid).
+- Keep `shouldProcess`, per-row error formatting and the sequential loop unchanged.
+- Extract the ZIP/status logic that currently lives inline in `BatchFileList.svelte` into
+  `src/lib/batch.ts` (`downloadBatchZip(items, zipBaseName)`, `batchStatusLabel`,
+  `batchStatusClass`) and reuse it from `BatchFileList` and `ExhibitFileList` without behaviour
+  changes.
+
+### Naming helper (`src/lib/exhibit-naming.ts`)
+
+```ts
+export const buildExhibitLabel = (prefix: string, number: number) => `${prefix.trim()} ${number}`;
+
+export const buildExhibitFileName = (options: {
+	prefix: string;
+	number: number;
+	highestNumber: number;
+	originalName: string;
+}): string => {
+	const base = options.originalName.replace(/\.pdf$/i, '');
+	const slug = options.prefix
+		.trim()
+		.replace(/\s+/g, '_')
+		.replace(/[/\\:*?"<>|\u0000-\u001f]/g, '');
+	const width = Math.max(2, String(options.highestNumber).length);
+	return `${slug}_${String(options.number).padStart(width, '0')}_${base}.pdf`;
+};
+```
+
+### Stamping
+
+- Load the PDF with pdf-lib, embed `StandardFonts.HelveticaBold`, draw the label on page 0 (or all
+  pages), save.
+- Result name from the naming helper (or the original name when renaming is off). The batch result
+  keeps the bytes in memory for download/ZIP.
+- Numbering is frozen at run start; `process` resolves `numbers.get(item.id) ?? freeze(item)`.
+
+## Files changed
+
+- `src/routes/tools/exhibits/+page.svelte` — new route.
+- `src/lib/components/ExhibitFileList.svelte` — reorderable list with status/downloads.
+- `src/lib/exhibit-naming.ts` — label + filename helpers.
+- `src/lib/batch.ts`, `src/lib/components/BatchFileList.svelte` — `runBatch` item context, shared
+  ZIP/status helpers.
+- `src/lib/pdf-text-overlay.ts`, `src/lib/pdf-errors.ts`, `src/lib/pdf-thumbnails.ts` — shared
+  helpers (whichever plan ships first creates them).
+- `src/lib/tools.ts`, `src/routes/+page.svelte` — registry + icon map (`Files`).
+- `tests/e2e/exhibits.spec.ts` — new spec.
+- `agents.md` — route, batch and shared-helper documentation.
+
+## Implementation phases
+
+1. Shared helpers (`pdf-text-overlay`, `pdf-errors`, page renderer) + stamp/compress regression.
+2. Batch refactor: `runBatch` item context, ZIP/status extraction, `BatchFileList` unchanged in
+   behaviour.
+3. Naming helper + list component with reorder, live labels and selection.
+4. Route: options, stamping, per-row results, ZIP, error rows.
+5. Preview panel.
+6. Registry/icon/docs.
+7. Playwright coverage + command gauntlet.
+
+## Verification
+
+- Three PDFs (1, 2, 3 pages), reorder the second to the front, prefix `Anlage K`, start 6, renaming
+  on → labels „Anlage K 6/7/8“, downloads named `Anlage_K_06_…`, `Anlage_K_07_…`, `Anlage_K_08_…`;
+  page 1 of each contains the label, page 2 is untouched (`getPageContentStreamCount` unchanged).
+- Start 98 with three files → padding switches to three digits (`098`, `099`, `100`).
+- Renaming off → downloads keep the original names; ZIP entries deduplicate on collisions.
+- „Auf jeder Seite stempeln“ → every page of every exhibit contains the label.
+- Reorder after a run → done rows keep their label and the hint is visible.
+- Prefix validation (empty), encrypted PDF (row error, queue continues), 30-file ZIP.
+- Single-page PDFs do not break the run.
+- `pnpm check`, targeted `pnpm test:e2e`, `pnpm build`, Prettier on touched files.
+
+## Risks
+
+- **Number drift after edits:** mitigated by frozen numbers + hint; no silent renumber.
+- **Drag-and-drop accessibility:** buttons remain the primary path and the tested one; DnD must have
+  a visible handle and keyboard alternative.
+- **Memory:** results stay in memory like every batch tool; the existing warning (>20 files or
+  > 25 MB) applies. The preview renders only one page — never a thumbnail array.
+- **Filename edge cases:** slugs from unusual prefixes (`Anlage K/1`) must not produce path
+  separators or empty names; validate and fall back to `Anlage`.
+- **Rotated scans:** the shared overlay compensates page rotation for the new tools; stamp output
+  must stay unchanged.
+- **Already-prefixed input files:** re-running the tool on its own output stacks prefixes. Document
+  it; no auto-detection in v1.
+
+## Out of scope
+
+- Grouping multiple PDFs into one Anlage.
+- Anlagenverzeichnis / index page (a merged table of contents is a follow-up candidate).
+- One merged „Anlagenkonvolut“ export.
+- Per-page counters (pagination plan).
+- Persisted prefixes or exhibit libraries.

plan/done/page-numbers-plan.md

@@ -0,0 +1,250 @@
+# Plan: Paginierung — fortlaufende Blattnummern mit Aktenzeichen
+
+## Goal
+
+Add a new tool **„Paginieren“** (`/tools/pagination`) that stamps every page of one PDF with an
+ascending sheet number — the way authorities paginate a case file („Bl. 26“) — optionally combined
+with a static free text (e.g. an Aktenzeichen `123 Ja 60/26`) that repeats on every page (default) or
+only on the first page. The same operation is offered as a follow-up action after **„PDFs
+zusammenfügen“**.
+
+Context: mail thread with Nikolai Klute (26.09.2026 / 06.10.2026). Two clarifications shape this
+plan: pagination needs a _simple_ free text next to the tool-generated number (no `{0}/{1}` template
+language), and that text should repeat „auf der ersten oder auf jeder Seite (Default)“.
+
+Related: `plan/done/stamp-plan.md` already references this plan as `page-numbers-plan`.
+
+---
+
+## Open decisions (defaults marked ✅)
+
+### D1 — Free-text model
+
+- ✅ **A. Static free text + tool-generated number.** No placeholder syntax: the number is always
+  produced by the tool, the free text is an optional label rendered with it. Directly matches
+  Nikolai's answer („Einfach nur ein Text im Zusammenhang mit der Seitenzahl“).
+- B. Template field (`Seite {n} von {total}`). Rejected for v1: more validation and support surface
+  than the use case needs; `{total}` is not requested.
+
+### D2 — What repeats, what increments
+
+- ✅ **A. Two independent scopes.** Page numbers always on every page (that is the point of
+  pagination). The free text has its own scope: „Auf jeder Seite“ (default) or „Nur auf der ersten
+  Seite“ — on page 2+ only the number remains.
+- B. One shared scope (text scope also gates numbering). Rejected: a first-page-only pagination is
+  not a thing.
+
+### D3 — Number format
+
+- ✅ **A. Select with four fixed formats** — `Bl. {n}` (default), `Seite {n}`, `S. {n}`, `{n}`.
+  Internally a prefix/suffix pair, so no user-visible template language, but „Bl.“ as the
+  German-authority default. Free text is prepended as `„{Text}, “`.
+- B. Free prefix/suffix inputs. More knobs, more invalid combinations.
+- C. One free format string. Reopened D1.
+
+### D4 — Look and placement
+
+- ✅ **A. Restrained authority style:** Helvetica, 11 pt (slider 8–18), black `#1a1a1a`, no frame,
+  no rotation, default position **unten mittig** with 28 pt margin; the six other positions are
+  selectable via the existing `getPositionCoords` presets.
+- B. Reuse the stamp tool's framed/bold look. Wrong semantics: a page number is a neutral mark, not
+  an authority stamp.
+
+### D5 — Files per run
+
+- ✅ **A. Exactly one PDF.** A Gesamtdokument is paginated in one pass; multi-document cases are
+  handled by „PDFs zusammenfügen“ + handoff. Continuous numbering across several dropped files is a
+  different (and silently wrong) semantic.
+- B. Batch with the same start number per file. Ambiguous for users; deferred until requested.
+
+### D6 — Integration into „PDF Zusammenfügen“
+
+- ✅ **A. Handoff to the pagination tool.** Merge writes the merged bytes into a `File`, queues it via
+  the existing in-memory file handoff, and navigates to `/tools/pagination`, where options and live
+  preview live. One implementation of pagination, preview included.
+- B. Inline pagination options on the merge page. Duplicated UI and no preview.
+
+### D7 — Preview renderer
+
+- ✅ **A. On-demand single-page renderer.** A paginated case file can have hundreds of pages;
+  `loadPdfDocument` rasterises _every_ page up front. A new
+  `loadPdfPageRenderer(bytes)` renders only the visible page and disposes the previous one.
+- B. Reuse `loadPdfDocument` (all thumbnails). Unacceptable for long documents.
+
+---
+
+## UX
+
+Route `/tools/pagination`, title „Paginieren“, registry entry after `stamp`:
+
+```ts
+{
+  slug: 'pagination',
+  title: 'Paginieren',
+  description: 'Versehen Sie alle Seiten mit fortlaufenden Blattnummern und optional einem Aktenzeichen.',
+  icon: 'list-ordered'
+}
+```
+
+Page layout (stamp tool as the pattern: options left, preview right):
+
+- **FileDropzone** (single PDF) — „PDF zum Paginieren hinzufügen“; shows the file name and page count
+  after loading.
+- **Options card**
+  - **Startnummer** (number input, default 1, min 1, max 99999) with hint „Seite 1 erhält diese
+    Nummer.“
+  - **Zusatztext (optional)** — e.g. Aktenzeichen, `maxlength="60"`, placeholder
+    „z. B. 123 Ja 60/26“, plus radio/checkbox „Auf jeder Seite“ (default) / „Nur auf der ersten
+    Seite“.
+  - **Zahlenformat** select: `Bl. {n}`, `Seite {n}`, `S. {n}`, `{n}`.
+  - **Position** select (default „Unten mittig“), **Schriftgröße** slider 8–18 pt (default 11).
+  - Live example line: `123 Ja 60/26, Bl. 26`.
+- **Preview card** — the current page rendered at reading size with an absolutely positioned overlay
+  (same technique as the stamp preview), page counter „Seite 3 von 42“, prev/next buttons and a
+  „Springe zu Seite“ number input (long documents). The overlay shows the number that page will
+  actually receive (`start + pageIndex`). Label it „Annäherung an die Ausgabe im PDF“.
+- **Primary action** „Paginieren & herunterladen“ → `{base}_paginiert.pdf`. Options are read at click
+  time, so the button can be pressed again after changing settings.
+- Errors: encrypted PDF → the shared German hint pointing to „Passwort entfernen“; text too long for
+  a page → German error instead of silent clipping.
+
+## Technical approach
+
+### Shared text overlay (`src/lib/pdf-text-overlay.ts`)
+
+Extract the reusable parts of `src/routes/tools/stamp/+page.svelte` into a module used by stamp,
+pagination and exhibit numbering:
+
+```ts
+export type TextOverlayOptions = {
+	font: PDFFont;
+	text: string;
+	size: number;
+	color: RGB;
+	position: OverlayPosition;
+	margin?: number;
+	padding?: number;
+	framed?: boolean;
+	borderWidth?: number;
+	rotation?: number; // degrees
+	minSize?: number; // shrink floor before throwing
+	compensatePageRotation?: boolean; // default false; new tools set true
+};
+
+export const drawTextOverlay = (page: PDFPage, options: TextOverlayOptions) => void;
+```
+
+- Owns fit-to-page shrinking (loop down to `minSize`), the rotated placement maths already present in
+  the stamp route (`getRotatedStampPlacement`), optional border, and the text draw.
+- The stamp route is rewired to call it with `framed: true`, `rotation: value` and its bold font;
+  behaviour must stay identical (guard: `tests/e2e/stamp.spec.ts`).
+- `compensatePageRotation` maps bottom-center on a `/Rotate 90` scan to the correct user-space anchor
+  and counter-rotates the text. Stamp keeps `false` so its output does not change.
+- Move `isEncryptedPdfError` / the encrypted-PDF message into `src/lib/pdf-errors.ts` so all three
+  tools share one wording.
+
+### Pagination
+
+```ts
+const numberText = `${formatPrefix}${startNumber + pageIndex}${formatSuffix}`;
+const textVisible = textScope === 'all' || pageIndex === 0;
+const line = textVisible && freeText.trim() ? `${freeText.trim()}, ${numberText}` : numberText;
+
+for (const [pageIndex, page] of pdfDoc.getPages().entries()) {
+	drawTextOverlay(page, {
+		font,
+		text: line,
+		size,
+		color: parseHexColor('#1a1a1a'),
+		position,
+		margin: 28,
+		compensatePageRotation: true
+	});
+}
+```
+
+- Embed one `StandardFonts.Helvetica` per document, save, name `${base}_paginiert.pdf`.
+- Page count comes from pdfjs (`numPages`) for the preview and from pdf-lib for processing; both are
+  cheap, no full rasterisation.
+- **Renderer:** extend `src/lib/pdf-thumbnails.ts` with
+  `loadPdfPageRenderer(bytes): Promise<{ pageCount, render(pageNumber), destroy() }>`; `render`
+  builds the canvas from the requested page's own viewport (mixed page sizes stay correct), revokes
+  the previous object URL, and `destroy` tears down the pdfjs loading task. Reused by the exhibit
+  tool's page-1 preview.
+
+### Merge integration
+
+- Generalise `src/lib/pending-files.ts`: `queueZipFiles` / `takeQueuedZipFiles` become
+  `queuePendingFiles` / `takePendingFiles` (same behaviour; update `src/routes/+page.svelte` and
+  `src/routes/tools/bea/+page.svelte`).
+- `src/routes/tools/merge/+page.svelte`: keep „PDFs zusammenfügen“ (direct download) and add
+  „Zusammenfügen & paginieren“, which merges, wraps the bytes in
+  `new File([bytes], 'zusammengefuegt.pdf', { type: 'application/pdf' })`, queues it and calls
+  `goto('/tools/pagination')`. Keep the change minimal — the page still uses older styling tokens;
+  do not restyle it in this task.
+- The pagination route consumes `takePendingFiles()` in `onMount`, accepts the first PDF and ignores
+  anything else defensively.
+
+### Registry and docs
+
+- `src/lib/tools.ts` + `iconMap` in `src/routes/+page.svelte` (`ListOrdered`).
+- `agents.md`: new route, shared overlay/error helpers, renderer, pending-file naming, merge handoff.
+
+## Files changed
+
+- `src/routes/tools/pagination/+page.svelte` — new route.
+- `src/lib/pdf-text-overlay.ts`, `src/lib/pdf-errors.ts` — extracted shared helpers.
+- `src/routes/tools/stamp/+page.svelte` — use the shared helpers (no behaviour change).
+- `src/lib/pdf-thumbnails.ts` — add `loadPdfPageRenderer`.
+- `src/lib/pending-files.ts`, `src/routes/+page.svelte`, `src/routes/tools/bea/+page.svelte` —
+  generic pending-file naming.
+- `src/routes/tools/merge/+page.svelte` — handoff button.
+- `src/lib/tools.ts`, `src/routes/+page.svelte` — registry + icon map.
+- `tests/e2e/pagination.spec.ts`, `tests/e2e/merge.spec.ts` — new/updated specs.
+- `agents.md` — structure and flow documentation.
+
+## Implementation phases
+
+1. Extract `pdf-text-overlay.ts` + `pdf-errors.ts`, rewire stamp, keep `stamp.spec.ts` green.
+2. Add `loadPdfPageRenderer` and use it for the preview.
+3. Build the pagination route (options, live preview, export, errors).
+4. Merge handoff + generic pending files.
+5. Registry/icon/docs.
+6. Playwright coverage + command gauntlet.
+
+## Verification
+
+- 3-page PDF, start 26, text `123 Ja 60/26`, all pages → each page's content stream contains
+  `123 Ja 60/26, Bl. 26/27/28`; page count and page order preserved; download named
+  `akte_paginiert.pdf`.
+- First-page-only text → page 1 contains the Aktenzeichen, page 2 contains `Bl. 2` but not the
+  Aktenzeichen; the original page content is preserved on every page.
+- Formats `Seite {n}` / `{n}` and empty free text → expected strings.
+- Preview: navigating to page 2 shows `Bl. 27` (start 26); changing the start number updates the
+  preview before export.
+- Rotated input (`createPreRotatedPdf`) → number appears at the visual bottom-center (test asserts
+  the draw coordinates in the content stream or compares stream text plus position).
+- Merge: two PDFs (1 + 2 pages) → „Zusammenfügen & paginieren“ lands on `/tools/pagination` with a
+  3-page document; running produces continuous `Bl. 1…3`.
+- Encrypted PDF → German error, no download.
+- `pnpm check`, targeted `pnpm test:e2e`, `pnpm build`, Prettier on touched files.
+
+## Risks
+
+- **Long documents:** never call `loadPdfDocument` here; one page in memory at a time. The preview
+  navigation must not leak object URLs or pdfjs tasks.
+- **Text length on narrow pages:** fit-to-page shrinks to `minSize`; below that, fail with a German
+  message rather than clipping.
+- **Unsupported characters:** StandardFonts use WinAnsi; validate the free text (e.g. no emoji) and
+  show a German hint instead of a pdf-lib save error.
+- **Rotated pages:** compensation is new logic; if the mapping turns out unreliable, ship v1 with a
+  visible warning for rotated pages instead of silently misplaced numbers.
+- **Preview fidelity:** browser font metrics differ slightly from pdf-lib; the panel is labelled as
+  an approximation.
+
+## Out of scope
+
+- Placeholder templates (`{total}`, Roman numerals, ranges) and numbering only selected pages.
+- Multiple files per run with continuous numbering (use merge first).
+- Persisted pagination settings.
+- Automatic pagination inside the beA archive export.

playwright.config.ts

@@ -8,7 +8,8 @@ const chromiumExecutable =
 	(existsSync('/usr/bin/chromium') ? '/usr/bin/chromium' : undefined);
 
 export default defineConfig({
-	testDir: './tests/e2e',
+	// `tests/unit` holds pure-function specs (no browser); Playwright runs both.
+	testDir: './tests',
 	fullyParallel: false,
 	retries: 0,
 	reporter: 'line',

src/lib/batch.ts

@@ -1,3 +1,6 @@
+import { zipSync } from 'fflate';
+import { downloadBlob } from './download';
+
 export type BatchItemStatus = 'pending' | 'processing' | 'done' | 'error';
 
 export type BatchItem = {
@@ -12,8 +15,11 @@ export type BatchItem = {
 export type BatchProcessResult = { bytes: Uint8Array; name: string };
 
 export type BatchRunOptions = {
-	/** Error message written to a row when `process` throws for it. */
+	/**
-	errorMessage?: string;
+	 * Error message written to a row when `process` throws for it. A function
+	 * receives the thrown error so tools can surface a specific German message.
+	 */
+	errorMessage?: string | ((error: unknown, file: File) => string);
 	/**
 	 * Optional predicate consulted before each item; when it returns `false`
 	 * (for example because the row was removed mid-run), the item is skipped.
@@ -31,10 +37,13 @@ export const createBatchItem = (file: File): BatchItem => ({
  * Processes the given items strictly one after another so only one PDF is in
  * flight at a time. Never throws: a failing item is marked as an error row and
  * the queue continues with the remaining files.
+ *
+ * `process` receives the item as well, so tools can resolve per-row data (for
+ * example the exhibit number frozen when the run started).
  */
 export const runBatch = async (
 	items: BatchItem[],
-	process: (file: File) => Promise<BatchProcessResult>,
+	process: (file: File, item: BatchItem) => Promise<BatchProcessResult>,
 	update: (id: string, patch: Partial<BatchItem>) => void,
 	options: BatchRunOptions = {}
 ): Promise<void> => {
@@ -45,7 +54,7 @@ export const runBatch = async (
 
 		update(item.id, { status: 'processing', errorMessage: null });
 		try {
-			const result = await process(item.file);
+			const result = await process(item.file, item);
 			update(item.id, {
 				status: 'done',
 				resultBytes: result.bytes,
@@ -58,7 +67,8 @@ export const runBatch = async (
 				status: 'error',
 				resultBytes: undefined,
 				resultName: undefined,
-				errorMessage
+				errorMessage:
+					typeof errorMessage === 'function' ? errorMessage(error, item.file) : errorMessage
 			});
 		}
 	}
@@ -69,3 +79,85 @@ export const formatBytes = (bytes: number) => {
 	if (bytes < 1024 * 1024) return `${(bytes / 1024).toFixed(1)} KB`;
 	return `${(bytes / (1024 * 1024)).toFixed(1)} MB`;
 };
+
+/** Badge colours for a batch row, shared by every batch list component. */
+export const batchStatusClass = (status: BatchItemStatus) => {
+	switch (status) {
+		case 'processing':
+			return 'bg-amber-100 text-amber-800';
+		case 'done':
+			return 'bg-emerald-100 text-emerald-800';
+		case 'error':
+			return 'bg-red-100 text-red-800';
+		default:
+			return 'bg-accent text-primary';
+	}
+};
+
+/** German badge label for a batch row. */
+export const batchStatusLabel = (status: BatchItemStatus) => {
+	switch (status) {
+		case 'processing':
+			return 'Verarbeite…';
+		case 'done':
+			return 'Fertig ✓';
+		case 'error':
+			return 'Fehler';
+		default:
+			return 'Wartet';
+	}
+};
+
+/** Above this many files (or one file above the threshold) memory gets tight. */
+const BATCH_MEMORY_FILE_COUNT = 20;
+const BATCH_MEMORY_FILE_BYTES = 25 * 1024 * 1024;
+
+/**
+ * Shared memory hint for batch tools: very many or very large files keep every
+ * result in memory until the page is closed.
+ */
+export const shouldWarnAboutBatchMemory = (items: BatchItem[]) =>
+	items.length > BATCH_MEMORY_FILE_COUNT ||
+	items.some((item) => item.file.size > BATCH_MEMORY_FILE_BYTES);
+
+/** Appends `_2`, `_3`, … when a name is already taken inside the archive. */
+export const uniqueEntryName = (name: string, usedNames: Set<string>) => {
+	if (!usedNames.has(name)) {
+		usedNames.add(name);
+		return name;
+	}
+
+	const dotIndex = name.lastIndexOf('.');
+	const base = dotIndex > 0 ? name.slice(0, dotIndex) : name;
+	const extension = dotIndex > 0 ? name.slice(dotIndex) : '';
+	let counter = 2;
+	let candidate = `${base}_2${extension}`;
+
+	while (usedNames.has(candidate)) {
+		counter += 1;
+		candidate = `${base}_${counter}${extension}`;
+	}
+
+	usedNames.add(candidate);
+	return candidate;
+};
+
+/**
+ * Bundles every finished row into one `{zipBaseName}_{YYYY-MM-DD}.zip`. Kept out
+ * of the component so the next batch tool (exhibits) reuses the naming and the
+ * duplicate handling instead of copying them.
+ */
+export const downloadBatchZip = (items: BatchItem[], zipBaseName: string) => {
+	const entries: Record<string, Uint8Array> = {};
+	const usedNames = new Set<string>();
+
+	for (const item of items) {
+		if (item.status !== 'done' || !item.resultBytes || !item.resultName) continue;
+		entries[uniqueEntryName(item.resultName, usedNames)] = item.resultBytes;
+	}
+
+	if (Object.keys(entries).length === 0) return;
+
+	const dateStamp = new Date().toISOString().slice(0, 10);
+	downloadBlob(zipSync(entries), `${zipBaseName}_${dateStamp}.zip`, 'application/zip');
+};

src/lib/components/AttachmentPreview.svelte

@@ -1,5 +1,6 @@
 <script lang="ts">
 	import { onMount } from 'svelte';
+	import { pdfLoadErrorMessage } from '$lib/pdf-errors';
 
 	import type { ZipAttachment } from '$lib/zip-processing';
 
@@ -98,7 +99,7 @@
 					await loadingTask.destroy();
 				} catch (error) {
 					console.error(`Failed to render preview for ${attachment.path}`, error);
-					previewError = 'PDF-Vorschau konnte nicht geladen werden.';
+					previewError = pdfLoadErrorMessage(error, 'PDF-Vorschau konnte nicht geladen werden.');
 				}
 			};
 
@@ -115,19 +116,19 @@
 <div class={className}>
 	{#if previewError}
 		<div
-			class="flex h-full min-h-0 items-center justify-center rounded-md border border-dashed border-primary-200 bg-primary-50 px-3 py-4 text-center text-[12px] text-primary-800"
+			class="border-primary-200 bg-primary-50 text-primary-800 flex h-full min-h-0 items-center justify-center rounded-md border border-dashed px-3 py-4 text-center text-[12px]"
 		>
 			{previewError}
 		</div>
 	{:else if imageUrl}
 		<img
 			alt={attachment.name}
-			class="block rounded-md border border-primary-100 bg-white object-contain"
+			class="border-primary-100 block rounded-md border bg-white object-contain"
 			src={imageUrl}
 		/>
 	{:else}
 		<div
-			class="flex items-center justify-center rounded-md border border-dashed border-primary-200 bg-primary-50 px-3 py-4 text-center text-[12px] text-primary-800"
+			class="border-primary-200 bg-primary-50 text-primary-800 flex items-center justify-center rounded-md border border-dashed px-3 py-4 text-center text-[12px]"
 		>
 			Vorschau wird erstellt
 		</div>

src/lib/components/BatchFileList.svelte

@@ -1,10 +1,14 @@
 <script lang="ts">
 	import { Download, RotateCcw, Trash2 } from '@lucide/svelte';
-	import { zipSync } from 'fflate';
 	import Button from '$lib/components/ui/button.svelte';
-	import { downloadBlob } from '$lib/download';
+	import {
-	import { formatBytes, type BatchItem } from '$lib/batch';
+		batchStatusClass,
-	import { RASTERIZATION_WARNING_BYTES } from '$lib/rasterization-limits';
+		batchStatusLabel,
+		downloadBatchZip,
+		formatBytes,
+		shouldWarnAboutBatchMemory,
+		type BatchItem
+	} from '$lib/batch';
 
 	type Props = {
 		items: BatchItem[];
@@ -22,68 +26,12 @@
 		doneItems.reduce((sum, item) => sum + (item.resultBytes?.byteLength ?? 0), 0)
 	);
 	const processingIndex = $derived(items.findIndex((item) => item.status === 'processing'));
-	const showMemoryWarning = $derived(
+	const showMemoryWarning = $derived(shouldWarnAboutBatchMemory(items));
-		items.length > 20 || items.some((item) => item.file.size > RASTERIZATION_WARNING_BYTES)
-	);
 
-	const uniqueEntryName = (name: string, usedNames: Set<string>) => {
+	const downloadZip = () => downloadBatchZip(doneItems, zipBaseName);
-		if (!usedNames.has(name)) {
-			usedNames.add(name);
-			return name;
-		}
-		const dotIndex = name.lastIndexOf('.');
-		const base = dotIndex > 0 ? name.slice(0, dotIndex) : name;
-		const extension = dotIndex > 0 ? name.slice(dotIndex) : '';
-		let counter = 2;
-		let candidate = `${base}_2${extension}`;
-		while (usedNames.has(candidate)) {
-			counter += 1;
-			candidate = `${base}_${counter}${extension}`;
-		}
-		usedNames.add(candidate);
-		return candidate;
-	};
-
-	const downloadZip = () => {
-		const entries: Record<string, Uint8Array> = {};
-		const usedNames = new Set<string>();
-		for (const item of doneItems) {
-			if (!item.resultBytes || !item.resultName) continue;
-			entries[uniqueEntryName(item.resultName, usedNames)] = item.resultBytes;
-		}
-		if (Object.keys(entries).length === 0) return;
-		const dateStamp = new Date().toISOString().slice(0, 10);
-		downloadBlob(zipSync(entries), `${zipBaseName}_${dateStamp}.zip`, 'application/zip');
-	};
-
-	const statusChipClass = (status: BatchItem['status']) => {
-		switch (status) {
-			case 'processing':
-				return 'bg-amber-100 text-amber-800';
-			case 'done':
-				return 'bg-emerald-100 text-emerald-800';
-			case 'error':
-				return 'bg-red-100 text-red-800';
-			default:
-				return 'bg-accent text-primary';
-		}
-	};
-
-	const statusLabel = (status: BatchItem['status']) => {
-		switch (status) {
-			case 'processing':
-				return 'Verarbeite…';
-			case 'done':
-				return 'Fertig ✓';
-			case 'error':
-				return 'Fehler';
-			default:
-				return 'Wartet';
-		}
-	};
 </script>
 
-<div class="rounded-2xl border border-border bg-card p-4 space-y-3">
+<div class="space-y-3 rounded-2xl border border-border bg-card p-4">
 	<div class="flex flex-wrap items-center justify-between gap-2">
 		<h2 class="text-lg font-semibold text-foreground">Dateien ({items.length})</h2>
 		{#if doneItems.length > 0}
@@ -123,18 +71,18 @@
 				</div>
 
 				<span
-					class="shrink-0 rounded-full px-2.5 py-0.5 text-xs font-semibold {statusChipClass(
+					class="shrink-0 rounded-full px-2.5 py-0.5 text-xs font-semibold {batchStatusClass(
 						item.status
 					)}"
 				>
-					{statusLabel(item.status)}
+					{batchStatusLabel(item.status)}
 				</span>
 
 				<div class="flex shrink-0 items-center gap-1">
 					{#if item.status === 'done' && item.resultBytes && item.resultName}
 						<button
 							type="button"
-							class="rounded-lg p-2 text-primary transition hover:bg-accent focus:outline-none focus-visible:ring-2 focus-visible:ring-primary-400"
+							class="focus-visible:ring-primary-400 rounded-lg p-2 text-primary transition hover:bg-accent focus:outline-none focus-visible:ring-2"
 							aria-label="{item.file.name} herunterladen"
 							title="{item.file.name} herunterladen"
 							onclick={() => onDownload(item)}
@@ -145,7 +93,7 @@
 					{#if item.status === 'error'}
 						<button
 							type="button"
-							class="rounded-lg p-2 text-primary transition hover:bg-accent focus:outline-none focus-visible:ring-2 focus-visible:ring-primary-400"
+							class="focus-visible:ring-primary-400 rounded-lg p-2 text-primary transition hover:bg-accent focus:outline-none focus-visible:ring-2"
 							aria-label="{item.file.name} erneut versuchen"
 							title="{item.file.name} erneut versuchen"
 							onclick={() => onRetry(item.id)}
@@ -155,7 +103,7 @@
 					{/if}
 					<button
 						type="button"
-						class="rounded-lg p-2 text-primary transition hover:bg-accent focus:outline-none focus-visible:ring-2 focus-visible:ring-primary-400 disabled:cursor-not-allowed disabled:opacity-40"
+						class="focus-visible:ring-primary-400 rounded-lg p-2 text-primary transition hover:bg-accent focus:outline-none focus-visible:ring-2 disabled:cursor-not-allowed disabled:opacity-40"
 						aria-label="{item.file.name} entfernen"
 						title="{item.file.name} entfernen"
 						disabled={item.status === 'processing'}

src/lib/components/ExhibitFileList.svelte

@@ -0,0 +1,269 @@
+<script lang="ts">
+	import { Download, Eye, GripVertical, RotateCcw, Trash2 } from '@lucide/svelte';
+	import Button from '$lib/components/ui/button.svelte';
+	import {
+		batchStatusClass,
+		batchStatusLabel,
+		downloadBatchZip,
+		formatBytes,
+		shouldWarnAboutBatchMemory,
+		type BatchItem
+	} from '$lib/batch';
+
+	type Props = {
+		items: BatchItem[];
+		/** Resolved stamp label per row; frozen once the row was created. */
+		labels: Record<string, string>;
+		/** Renamed file per row, or `null` when renaming is switched off. */
+		fileNames: Record<string, string | null>;
+		selectedId: string | null;
+		/** Base file name of the bulk ZIP, e.g. `anlagen` → `anlagen_2026-10-06.zip`. */
+		zipBaseName: string;
+		/** Reordering and preview selection are blocked while a run is active. */
+		disabled?: boolean;
+		onSelect: (id: string) => void;
+		onMove: (from: number, to: number) => void;
+		onDownload: (item: BatchItem) => void;
+		onRemove: (id: string) => void;
+		onRetry: (id: string) => void;
+	};
+
+	let {
+		items,
+		labels,
+		fileNames,
+		selectedId,
+		zipBaseName,
+		disabled = false,
+		onSelect,
+		onMove,
+		onDownload,
+		onRemove,
+		onRetry
+	}: Props = $props();
+
+	let draggingId = $state<string | null>(null);
+	let dragOverId = $state<string | null>(null);
+
+	const doneItems = $derived(items.filter((item) => item.status === 'done'));
+	const totalResultBytes = $derived(
+		doneItems.reduce((sum, item) => sum + (item.resultBytes?.byteLength ?? 0), 0)
+	);
+	const processingIndex = $derived(items.findIndex((item) => item.status === 'processing'));
+	const showMemoryWarning = $derived(shouldWarnAboutBatchMemory(items));
+
+	const downloadZip = () => downloadBatchZip(doneItems, zipBaseName);
+
+	const moveUp = (index: number) => {
+		if (disabled || index === 0) return;
+		onMove(index, index - 1);
+	};
+
+	const moveDown = (index: number) => {
+		if (disabled || index === items.length - 1) return;
+		onMove(index, index + 1);
+	};
+
+	const handleDragStart = (event: DragEvent, item: BatchItem) => {
+		if (disabled) return;
+		draggingId = item.id;
+		event.dataTransfer?.setData('text/plain', item.id);
+		if (event.dataTransfer) event.dataTransfer.effectAllowed = 'move';
+	};
+
+	const handleDragOver = (event: DragEvent, item: BatchItem) => {
+		if (disabled || !draggingId || draggingId === item.id) return;
+		event.preventDefault();
+		dragOverId = item.id;
+	};
+
+	const handleDrop = (event: DragEvent, item: BatchItem) => {
+		event.preventDefault();
+		const sourceId = draggingId;
+		draggingId = null;
+		dragOverId = null;
+		if (disabled || !sourceId || sourceId === item.id) return;
+
+		const from = items.findIndex((entry) => entry.id === sourceId);
+		const to = items.findIndex((entry) => entry.id === item.id);
+		if (from === -1 || to === -1) return;
+		onMove(from, to);
+	};
+
+	const handleDragEnd = () => {
+		draggingId = null;
+		dragOverId = null;
+	};
+</script>
+
+<div class="space-y-3 rounded-2xl border border-border bg-card p-4">
+	<div class="flex flex-wrap items-center justify-between gap-2">
+		<h2 class="text-lg font-semibold text-foreground">Anlagen ({items.length})</h2>
+		{#if doneItems.length > 0}
+			<p class="text-sm text-primary">
+				Ergebnisse gesamt: <span class="font-semibold">{formatBytes(totalResultBytes)}</span>
+			</p>
+		{/if}
+	</div>
+
+	{#if processingIndex !== -1}
+		<p class="text-sm text-primary" role="status">
+			Datei {processingIndex + 1} von {items.length} wird verarbeitet…
+		</p>
+	{/if}
+
+	{#if showMemoryWarning}
+		<div class="rounded-lg border border-amber-200 bg-amber-50 p-3 text-sm text-amber-800">
+			Bei sehr vielen oder sehr großen Dateien kann der Arbeitsspeicher knapp werden. Laden Sie
+			fertige Ergebnisse früh herunter und entfernen Sie sie aus der Liste.
+		</div>
+	{/if}
+
+	<ul class="divide-y divide-border">
+		{#each items as item, index (item.id)}
+			{@const label = labels[item.id] ?? ''}
+			{@const renamed = fileNames[item.id] ?? null}
+			<li
+				class="flex flex-wrap items-center gap-3 py-3 {dragOverId === item.id
+					? 'bg-accent/40'
+					: ''} {draggingId === item.id ? 'opacity-60' : ''}"
+				data-exhibit-item={item.file.name}
+				data-exhibit-index={index + 1}
+				data-exhibit-label={label}
+				draggable={!disabled}
+				ondragstart={(event) => handleDragStart(event, item)}
+				ondragover={(event) => handleDragOver(event, item)}
+				ondrop={(event) => handleDrop(event, item)}
+				ondragend={handleDragEnd}
+			>
+				<div class="flex shrink-0 items-center gap-1">
+					<span
+						class="cursor-grab p-1 text-muted-foreground {disabled ? 'opacity-40' : ''}"
+						aria-hidden="true"
+						title="Ziehen zum Verschieben"
+					>
+						<GripVertical class="h-4 w-4" />
+					</span>
+					<span
+						class="flex h-6 w-6 items-center justify-center rounded-full bg-accent text-xs font-bold text-primary"
+						title="Position in der Liste"
+					>
+						{index + 1}
+					</span>
+					<div class="flex flex-col">
+						<button
+							type="button"
+							class="rounded p-0.5 text-primary transition hover:bg-accent focus:outline-none focus-visible:ring-2 focus-visible:ring-ring disabled:cursor-not-allowed disabled:opacity-40"
+							aria-label="{item.file.name} nach oben verschieben"
+							title="Nach oben"
+							disabled={disabled || index === 0}
+							onclick={() => moveUp(index)}
+						>
+							<svg
+								viewBox="0 0 24 24"
+								class="h-3 w-3"
+								fill="none"
+								stroke="currentColor"
+								stroke-width="3"
+								aria-hidden="true"><path d="M6 15l6-6 6 6" /></svg
+							>
+						</button>
+						<button
+							type="button"
+							class="rounded p-0.5 text-primary transition hover:bg-accent focus:outline-none focus-visible:ring-2 focus-visible:ring-ring disabled:cursor-not-allowed disabled:opacity-40"
+							aria-label="{item.file.name} nach unten verschieben"
+							title="Nach unten"
+							disabled={disabled || index === items.length - 1}
+							onclick={() => moveDown(index)}
+						>
+							<svg
+								viewBox="0 0 24 24"
+								class="h-3 w-3"
+								fill="none"
+								stroke="currentColor"
+								stroke-width="3"
+								aria-hidden="true"><path d="M6 9l6 6 6-6" /></svg
+							>
+						</button>
+					</div>
+				</div>
+
+				<div class="min-w-0 flex-1">
+					<p class="truncate text-sm font-semibold text-foreground">
+						{label}
+					</p>
+					<p class="truncate text-xs text-primary">{item.file.name}</p>
+					{#if renamed}
+						<p class="truncate text-xs text-muted-foreground" data-exhibit-filename>
+							→ {renamed}
+						</p>
+					{/if}
+					{#if item.status === 'error' && item.errorMessage}
+						<p class="mt-0.5 text-xs text-red-700" role="alert">{item.errorMessage}</p>
+					{/if}
+				</div>
+
+				<span
+					class="shrink-0 rounded-full px-2.5 py-0.5 text-xs font-semibold {batchStatusClass(
+						item.status
+					)}"
+				>
+					{batchStatusLabel(item.status)}
+				</span>
+
+				<div class="flex shrink-0 items-center gap-1">
+					<button
+						type="button"
+						class="focus-visible:ring-primary-400 rounded-lg p-2 text-primary transition hover:bg-accent focus:outline-none focus-visible:ring-2 disabled:cursor-not-allowed disabled:opacity-40 aria-pressed:bg-accent"
+						aria-label="Vorschau für {item.file.name}"
+						title="Vorschau für {item.file.name}"
+						aria-pressed={selectedId === item.id}
+						{disabled}
+						onclick={() => onSelect(item.id)}
+					>
+						<Eye class="h-4 w-4" />
+					</button>
+					{#if item.status === 'done' && item.resultBytes && item.resultName}
+						<button
+							type="button"
+							class="focus-visible:ring-primary-400 rounded-lg p-2 text-primary transition hover:bg-accent focus:outline-none focus-visible:ring-2"
+							aria-label="{item.file.name} herunterladen"
+							title="{item.file.name} herunterladen"
+							onclick={() => onDownload(item)}
+						>
+							<Download class="h-4 w-4" />
+						</button>
+					{/if}
+					{#if item.status === 'error'}
+						<button
+							type="button"
+							class="focus-visible:ring-primary-400 rounded-lg p-2 text-primary transition hover:bg-accent focus:outline-none focus-visible:ring-2 disabled:cursor-not-allowed disabled:opacity-40"
+							aria-label="{item.file.name} erneut versuchen"
+							title="{item.file.name} erneut versuchen"
+							{disabled}
+							onclick={() => onRetry(item.id)}
+						>
+							<RotateCcw class="h-4 w-4" />
+						</button>
+					{/if}
+					<button
+						type="button"
+						class="focus-visible:ring-primary-400 rounded-lg p-2 text-primary transition hover:bg-accent focus:outline-none focus-visible:ring-2 disabled:cursor-not-allowed disabled:opacity-40"
+						aria-label="{item.file.name} entfernen"
+						title="{item.file.name} entfernen"
+						disabled={item.status === 'processing'}
+						onclick={() => onRemove(item.id)}
+					>
+						<Trash2 class="h-4 w-4" />
+					</button>
+				</div>
+			</li>
+		{/each}
+	</ul>
+
+	{#if doneItems.length >= 2}
+		<div class="flex justify-end pt-1">
+			<Button onclick={downloadZip} icon={Download}>Alle herunterladen</Button>
+		</div>
+	{/if}
+</div>

src/lib/components/PaginationPreview.svelte

@@ -0,0 +1,164 @@
+<script lang="ts">
+	import { ChevronLeft, ChevronRight } from '@lucide/svelte';
+	import Button from '$lib/components/ui/button.svelte';
+	import { MIN_FONT_SIZE, PAGE_NUMBER_COLOR, PAGE_NUMBER_MARGIN } from '$lib/pdf-pagination';
+	import { getPreviewPositionStyle, type OverlayPosition } from '$lib/pdf-overlay';
+	import { getTextFitScale } from '$lib/pdf-preview-text';
+	import { PDF_PREVIEW_SCALE, type PdfPageImage } from '$lib/pdf-thumbnails';
+
+	type Props = {
+		/** Rendered page bitmap, or `null` while the first render is pending. */
+		preview: PdfPageImage | null;
+		/** Message shown instead of the bitmap when rendering failed. */
+		error: string | null;
+		/** Label the export will stamp on this page. */
+		label: string;
+		fontSize: number;
+		position: OverlayPosition;
+		currentPage: number;
+		pageCount: number;
+		onRetry: () => void;
+		onShowPage: (pageNumber: number) => void;
+	};
+
+	let {
+		preview,
+		error,
+		label,
+		fontSize,
+		position,
+		currentPage,
+		pageCount,
+		onRetry,
+		onShowPage
+	}: Props = $props();
+
+	const pageSize = $derived(
+		preview
+			? { width: preview.width / PDF_PREVIEW_SCALE, height: preview.height / PDF_PREVIEW_SCALE }
+			: null
+	);
+
+	/**
+	 * The export shrinks a label that does not fit (down to `MIN_FONT_SIZE`), so
+	 * the preview applies the same factor instead of clipping.
+	 */
+	const fit = $derived.by(() => {
+		if (!pageSize) return { scale: 1, shrunk: false, tooLong: false };
+
+		const raw = getTextFitScale(
+			label,
+			fontSize,
+			pageSize.width - PAGE_NUMBER_MARGIN * 2,
+			pageSize.height - PAGE_NUMBER_MARGIN * 2
+		);
+		const minScale = MIN_FONT_SIZE / fontSize;
+
+		return { scale: Math.max(raw, minScale), shrunk: raw < 0.999, tooLong: raw < minScale };
+	});
+
+	const previewFontSize = $derived(
+		preview ? (fontSize * fit.scale * PDF_PREVIEW_SCALE * 100) / preview.width : 0
+	);
+	const shrunkFontSize = $derived(Math.max(MIN_FONT_SIZE, Math.round(fontSize * fit.scale)));
+</script>
+
+<section
+	class="flex flex-col gap-4 rounded-2xl border border-border bg-card p-5"
+	aria-labelledby="pagination-preview-title"
+>
+	<div class="flex items-start justify-between gap-3">
+		<div>
+			<h2 id="pagination-preview-title" class="text-lg font-semibold text-foreground">Vorschau</h2>
+			<p class="mt-1 text-xs text-muted-foreground">Annäherung an die Ausgabe im PDF</p>
+		</div>
+		<span class="text-xs font-semibold text-primary">Seite {currentPage} von {pageCount}</span>
+	</div>
+
+	{#if error}
+		<div
+			class="flex flex-col items-center gap-3 rounded-lg border border-border bg-muted/30 p-6 text-center"
+			role="alert"
+		>
+			<p class="text-sm text-foreground">{error}</p>
+			<Button variant="tertiary" onclick={onRetry}>Erneut versuchen</Button>
+		</div>
+	{:else if preview}
+		<div
+			class="relative mx-auto w-full max-w-lg overflow-hidden rounded-lg border border-border bg-white shadow-sm"
+			style="container-type: inline-size; aspect-ratio: {preview.width} / {preview.height};"
+		>
+			<img
+				src={preview.imageUrl}
+				alt="Vorschau von Seite {currentPage}"
+				class="block h-full w-full"
+			/>
+			<div
+				class="absolute max-w-[92%] leading-tight whitespace-nowrap"
+				style="{getPreviewPositionStyle(
+					position
+				)} font-size: {previewFontSize}cqw; color: {PAGE_NUMBER_COLOR};"
+				data-testid="pagination-preview"
+				data-position={position}
+			>
+				{label}
+			</div>
+		</div>
+	{:else}
+		<div
+			class="flex aspect-[1/1.414] items-center justify-center rounded-lg border border-border bg-muted/30 text-xs text-muted-foreground"
+		>
+			Vorschau wird geladen …
+		</div>
+	{/if}
+
+	{#if fit.tooLong}
+		<p class="text-xs text-destructive" role="status">
+			Der Text ist für diese Seite zu lang. Kürzen Sie den Zusatztext oder wählen Sie ein kürzeres
+			Zahlenformat.
+		</p>
+	{:else if fit.shrunk}
+		<p class="text-xs text-muted-foreground" role="status">
+			Auf dieser Seite wird der Text auf {shrunkFontSize} pt verkleinert.
+		</p>
+	{/if}
+
+	{#if pageCount > 1}
+		<div class="flex flex-wrap items-center justify-center gap-3">
+			<Button
+				variant="tertiary"
+				class="min-w-0 px-3"
+				onclick={() => onShowPage(currentPage - 1)}
+				disabled={currentPage === 1}
+				aria-label="Vorherige Seite"
+			>
+				<ChevronLeft aria-hidden="true" />
+			</Button>
+			<Button
+				variant="tertiary"
+				class="min-w-0 px-3"
+				onclick={() => onShowPage(currentPage + 1)}
+				disabled={currentPage === pageCount}
+				aria-label="Nächste Seite"
+			>
+				<ChevronRight aria-hidden="true" />
+			</Button>
+			<label class="flex items-center gap-2 text-sm text-foreground" for="pagination-page">
+				<span class="text-xs text-muted-foreground">Seite</span>
+				<input
+					id="pagination-page"
+					type="number"
+					inputmode="numeric"
+					step="1"
+					min="1"
+					max={pageCount}
+					value={currentPage}
+					oninput={(event) => onShowPage(Number(event.currentTarget.value))}
+					onblur={(event) => (event.currentTarget.value = String(currentPage))}
+					aria-label="Springe zu Seite"
+					class="w-20 rounded-lg border border-input bg-background px-2 py-1 text-sm"
+				/>
+			</label>
+		</div>
+	{/if}
+</section>

src/lib/components/PdfSplitDialog.svelte

@@ -3,6 +3,7 @@
 	import { X } from '@lucide/svelte';
 	import Button from '$lib/components/ui/button.svelte';
 	import PdfPageGrid from '$lib/components/PdfPageGrid.svelte';
+	import { pdfLoadErrorMessage, pdfProcessingErrorMessage } from '$lib/pdf-errors';
 	import { loadPdfDocument, type PdfDocumentHandle } from '$lib/pdf-thumbnails';
 	import {
 		createAttachmentFromPages,
@@ -172,7 +173,7 @@
 			onApply(await buildResult(groups));
 		} catch (error) {
 			console.error(`Failed to split PDF attachment ${source.path}`, error);
-			splitError = 'Das PDF konnte nicht geteilt werden.';
+			splitError = pdfProcessingErrorMessage(error, 'Das PDF konnte nicht geteilt werden.');
 		} finally {
 			isProcessing = false;
 		}
@@ -209,7 +210,7 @@
 				console.error(`Failed to load PDF attachment ${source.path}`, error);
 
 				if (!cancelled) {
-					loadError = 'PDF konnte nicht geladen werden.';
+					loadError = pdfLoadErrorMessage(error);
 				}
 			}
 		})();
@@ -237,16 +238,16 @@
 		data-split-dialog
 		tabindex="-1"
 	>
-		<header class="flex items-center justify-between gap-3 border-b border-primary-100 px-5 py-4">
+		<header class="border-primary-100 flex items-center justify-between gap-3 border-b px-5 py-4">
 			<div class="min-w-0">
-				<h2 class="text-[16px] font-bold text-primary-900">PDF teilen</h2>
+				<h2 class="text-primary-900 text-[16px] font-bold">PDF teilen</h2>
-				<p class="truncate text-[13px] text-primary-700" title={source.name}>
+				<p class="text-primary-700 truncate text-[13px]" title={source.name}>
 					{source.name} — {pageCount} Seite{pageCount === 1 ? '' : 'n'}
 				</p>
 			</div>
 			<button
 				type="button"
-				class="flex h-8 w-8 shrink-0 cursor-pointer items-center justify-center rounded-full border border-primary-200 bg-white text-primary-700 transition hover:border-primary-400 hover:bg-primary-50"
+				class="border-primary-200 text-primary-700 hover:border-primary-400 hover:bg-primary-50 flex h-8 w-8 shrink-0 cursor-pointer items-center justify-center rounded-full border bg-white transition"
 				aria-label="Teilen abbrechen"
 				onclick={onClose}
 			>
@@ -256,7 +257,7 @@
 
 		<div class="flex-1 space-y-4 overflow-y-auto px-5 py-4">
 			<div
-				class="inline-flex flex-wrap items-center rounded-[16px] border border-primary-200 bg-white p-0.5"
+				class="border-primary-200 inline-flex flex-wrap items-center rounded-[16px] border bg-white p-0.5"
 				role="radiogroup"
 				aria-label="Art des Teilens"
 			>
@@ -283,10 +284,10 @@
 			</div>
 
 			{#if mode === 'everyN'}
-				<label class="flex flex-wrap items-center gap-2 text-[13px] font-semibold text-primary-900">
+				<label class="text-primary-900 flex flex-wrap items-center gap-2 text-[13px] font-semibold">
 					Seiten pro Teildokument
 					<input
-						class="w-20 rounded-md border border-primary-200 bg-white px-2 py-1 text-[13px] font-medium text-primary-900 outline-none transition focus:border-primary-400 focus:ring-2 focus:ring-primary-200"
+						class="border-primary-200 text-primary-900 focus:border-primary-400 focus:ring-primary-200 w-20 rounded-md border bg-white px-2 py-1 text-[13px] font-medium transition outline-none focus:ring-2"
 						type="number"
 						min={2}
 						value={chunkSize}
@@ -298,7 +299,7 @@
 			{/if}
 
 			{#if mode !== 'manual' && pageCount > 0}
-				<p class="text-[13px] font-medium text-primary-700" aria-live="polite">
+				<p class="text-primary-700 text-[13px] font-medium" aria-live="polite">
 					Es werden {bulkChunks.length}
 					Teildokument{bulkChunks.length === 1 ? '' : 'e'} erstellt.
 				</p>
@@ -329,7 +330,7 @@
 				</PdfPageGrid>
 			{:else}
 				<div
-					class="flex items-center justify-center rounded-md border border-dashed border-primary-200 bg-primary-50 px-4 py-10 text-[13px] text-primary-700"
+					class="border-primary-200 bg-primary-50 text-primary-700 flex items-center justify-center rounded-md border border-dashed px-4 py-10 text-[13px]"
 				>
 					Vorschau wird erstellt
 				</div>
@@ -340,7 +341,7 @@
 					<label class="flex min-w-0 flex-1 items-center gap-2">
 						<span class="sr-only">Name des Teildokuments</span>
 						<input
-							class="w-full min-w-40 rounded-md border border-primary-200 bg-white px-3 py-1.5 text-[13px] font-semibold text-primary-900 outline-none transition focus:border-primary-400 focus:ring-2 focus:ring-primary-200"
+							class="border-primary-200 text-primary-900 focus:border-primary-400 focus:ring-primary-200 w-full min-w-40 rounded-md border bg-white px-3 py-1.5 text-[13px] font-semibold transition outline-none focus:ring-2"
 							type="text"
 							placeholder={selectedPages.size > 0
 								? defaultGroupName([...selectedPages])
@@ -359,7 +360,7 @@
 						Als Teildokument übernehmen
 					</Button>
 				</div>
-				<p class="text-[13px] text-primary-700" aria-live="polite">
+				<p class="text-primary-700 text-[13px]" aria-live="polite">
 					{selectedPages.size} von {pageCount} Seiten ausgewählt
 				</p>
 			{/if}
@@ -368,17 +369,17 @@
 				<ul class="flex flex-col gap-2">
 					{#each assignedGroups as group, index (index)}
 						<li
-							class="flex flex-wrap items-center gap-2 rounded-xl border border-primary-200 bg-primary-50 px-3 py-1.5"
+							class="border-primary-200 bg-primary-50 flex flex-wrap items-center gap-2 rounded-xl border px-3 py-1.5"
 						>
-							<span class="min-w-0 flex-1 truncate text-[13px] font-semibold text-primary-900">
+							<span class="text-primary-900 min-w-0 flex-1 truncate text-[13px] font-semibold">
 								{group.name}
 							</span>
-							<span class="text-[12px] font-medium text-primary-700">
+							<span class="text-primary-700 text-[12px] font-medium">
 								{describePages(group.pages)}
 							</span>
 							<button
 								type="button"
-								class="flex h-6 w-6 cursor-pointer items-center justify-center rounded-full text-primary-600 transition hover:bg-white hover:text-red-700"
+								class="text-primary-600 flex h-6 w-6 cursor-pointer items-center justify-center rounded-full transition hover:bg-white hover:text-red-700"
 								aria-label={`Zuordnung „${group.name}“ aufheben`}
 								onclick={() => removeGroup(index)}
 							>
@@ -395,9 +396,9 @@
 				</div>
 			{/if}
 
-			<label class="flex items-center gap-2 text-[13px] font-medium text-primary-900">
+			<label class="text-primary-900 flex items-center gap-2 text-[13px] font-medium">
 				<input
-					class="h-4 w-4 accent-primary-700"
+					class="accent-primary-700 h-4 w-4"
 					type="checkbox"
 					checked={keepSource}
 					onchange={(event) => {
@@ -409,7 +410,7 @@
 		</div>
 
 		<footer
-			class="flex flex-wrap items-center justify-end gap-2 border-t border-primary-100 px-5 py-4"
+			class="border-primary-100 flex flex-wrap items-center justify-end gap-2 border-t px-5 py-4"
 		>
 			<Button type="button" variant="bordered" disabled={isProcessing} onclick={onClose}>
 				Abbrechen

src/lib/components/ProcessedZipArchiveEditor.svelte

@@ -5,6 +5,7 @@
 	import Button from '$lib/components/ui/button.svelte';
 	import * as AlertDialog from '$lib/components/ui/alert-dialog/index.js';
 	import PdfSplitDialog from '$lib/components/PdfSplitDialog.svelte';
+	import { pdfProcessingErrorMessage } from '$lib/pdf-errors';
 	import SubDocumentEditor from '$lib/components/SubDocumentEditor.svelte';
 	import {
 		applyPdfSplit,
@@ -447,7 +448,7 @@
 			}
 		} catch (error) {
 			console.error(`Failed to export archive ${archive.name}`, error);
-			mergeError = 'PDF konnte nicht erstellt werden.';
+			mergeError = pdfProcessingErrorMessage(error, 'PDF konnte nicht erstellt werden.');
 		} finally {
 			isMerging = false;
 		}
@@ -470,7 +471,10 @@
 				`Failed to export sub-document "${subDocument.name}" from archive ${archive.name}`,
 				error
 			);
-			mergeError = `Teildokument „${subDocument.name}“ konnte nicht als PDF erstellt werden.`;
+			mergeError = pdfProcessingErrorMessage(
+				error,
+				`Teildokument „${subDocument.name}“ konnte nicht als PDF erstellt werden.`
+			);
 		} finally {
 			downloadingSubDocumentId = null;
 		}
@@ -480,14 +484,14 @@
 <svelte:window onkeydown={handleWindowKeydown} />
 
 <section
-	class="flex flex-col gap-4 rounded-2xl border border-primary-100 bg-white px-4 py-4 shadow-sm"
+	class="border-primary-100 flex flex-col gap-4 rounded-2xl border bg-white px-4 py-4 shadow-sm"
 >
 	<header class="flex flex-wrap items-baseline justify-between gap-2 text-primary">
 		<div class="min-w-0 flex-1">
 			<label class="block min-w-0">
 				<span class="sr-only">Archivname</span>
 				<input
-					class="w-full max-w-xl rounded-md border border-primary-200 bg-white px-3 py-2 text-[16px] font-bold text-primary-900 outline-none transition focus:border-primary-400 focus:ring-2 focus:ring-primary-200"
+					class="border-primary-200 text-primary-900 focus:border-primary-400 focus:ring-primary-200 w-full max-w-xl rounded-md border bg-white px-3 py-2 text-[16px] font-bold transition outline-none focus:ring-2"
 					type="text"
 					value={archiveName}
 					draggable="false"
@@ -532,7 +536,7 @@
 			{#if hasSubDocuments}
 				<div
 					class={cn(
-						'inline-flex items-center rounded-[16px] border border-primary-200 bg-white p-0.5',
+						'border-primary-200 inline-flex items-center rounded-[16px] border bg-white p-0.5',
 						downloadingSubDocumentId !== null ? 'opacity-60' : ''
 					)}
 					role="radiogroup"
@@ -584,7 +588,7 @@
 
 	{#if groupingMode}
 		<div
-			class="flex flex-wrap items-center gap-3 rounded-xl border border-primary-200 bg-primary-50 px-4 py-2 text-[13px] font-medium text-primary-900"
+			class="border-primary-200 bg-primary-50 text-primary-900 flex flex-wrap items-center gap-3 rounded-xl border px-4 py-2 text-[13px] font-medium"
 		>
 			<span aria-live="polite">
 				{selectedCount} Datei{selectedCount === 1 ? '' : 'en'} ausgewählt
@@ -634,10 +638,10 @@
 		{#each looseAttachments as attachment, index (attachment.path)}
 			<li
 				class={cn(
-					'flex flex-col shrink-0 items-stretch gap-2 rounded-xl border bg-accent p-2 text-primary transition',
+					'flex shrink-0 flex-col items-stretch gap-2 rounded-xl border bg-accent p-2 text-primary transition',
-					dropIndex === index ? 'border-primary-400 ring-1 ring-primary-200' : 'border-primary-100',
+					dropIndex === index ? 'border-primary-400 ring-primary-200 ring-1' : 'border-primary-100',
 					dragIndex === index ? 'opacity-60' : '',
-					selectedPaths.has(attachment.path) ? 'border-primary-500 ring-2 ring-primary-300' : ''
+					selectedPaths.has(attachment.path) ? 'border-primary-500 ring-primary-300 ring-2' : ''
 				)}
 				style={`width: ${thumbnailWidth}px;`}
 				draggable={groupingMode ? 'false' : 'true'}
@@ -648,9 +652,9 @@
 			>
 				{#if groupingMode}
 					<label class="flex cursor-pointer flex-col gap-2">
-						<div class="flex items-center gap-2 px-1 text-[13px] font-medium text-primary-900">
+						<div class="text-primary-900 flex items-center gap-2 px-1 text-[13px] font-medium">
 							<input
-								class="h-4 w-4 accent-primary-700"
+								class="accent-primary-700 h-4 w-4"
 								type="checkbox"
 								checked={selectedPaths.has(attachment.path)}
 								onchange={() => toggleSelection(attachment.path)}
@@ -661,7 +665,7 @@
 						</div>
 
 						<div
-							class="truncate text-[13px] font-medium leading-tight text-primary-900"
+							class="text-primary-900 truncate text-[13px] leading-tight font-medium"
 							title={attachment.name}
 						>
 							{attachment.name}
@@ -671,7 +675,7 @@
 				{:else}
 					<div class="flex min-w-0 flex-1 flex-row items-center gap-1 py-1">
 						<button
-							class="w-fit cursor-grab rounded-md border border-primary-200 bg-white px-2 py-1 text-sm font-semibold leading-none text-primary-700 active:cursor-grabbing"
+							class="border-primary-200 text-primary-700 w-fit cursor-grab rounded-md border bg-white px-2 py-1 text-sm leading-none font-semibold active:cursor-grabbing"
 							draggable="false"
 							type="button"
 							aria-label="Datei verschieben"
@@ -680,7 +684,7 @@
 						</button>
 
 						<div
-							class="min-w-0 flex-1 truncate text-[13px] font-medium leading-tight text-primary-900"
+							class="text-primary-900 min-w-0 flex-1 truncate text-[13px] leading-tight font-medium"
 							title={attachment.name}
 						>
 							{attachment.name}
@@ -703,7 +707,7 @@
 
 	{#if looseAttachments.length === 0 && subDocuments.length === 0}
 		<div
-			class="rounded-md border border-dashed border-primary-200 bg-primary-50 px-4 py-4 text-[13px] text-primary-700"
+			class="border-primary-200 bg-primary-50 text-primary-700 rounded-md border border-dashed px-4 py-4 text-[13px]"
 		>
 			Keine Dateien in diesem Archiv. Lade ein anderes ZIP, um weiterzuarbeiten.
 		</div>
@@ -758,7 +762,7 @@
 	}}
 >
 	<AlertDialog.Content class="max-w-sm">
-		<AlertDialog.Title class="text-base font-bold text-primary-900">
+		<AlertDialog.Title class="text-primary-900 text-base font-bold">
 			Datei entfernen?
 		</AlertDialog.Title>
 		<AlertDialog.Description>

src/lib/components/SinglePdfTool.svelte

@@ -0,0 +1,73 @@
+<script lang="ts">
+	import type { Snippet } from 'svelte';
+	import FileDropzone from '$lib/components/FileDropzone.svelte';
+	import ToolError from '$lib/components/ToolError.svelte';
+
+	type Props = {
+		title: string;
+		description: string;
+		file: File | null;
+		/** `0` while no PDF is loaded; switches the shell to the bare dropzone. */
+		pageCount: number;
+		loadingError: string | null;
+		error?: string | null;
+		onFilesSelected: (files: File[]) => void;
+		/** Extra toolbar buttons next to the file name. */
+		actions?: Snippet;
+		/** Main content, e.g. the page grid. */
+		children: Snippet;
+		/** Status line plus primary action, laid out `space-between`. */
+		footer: Snippet;
+	};
+
+	let {
+		title,
+		description,
+		file,
+		pageCount,
+		loadingError,
+		error,
+		onFilesSelected,
+		actions,
+		children,
+		footer
+	}: Props = $props();
+</script>
+
+<div class="mx-auto max-w-4xl space-y-6">
+	<div>
+		<h1 class="text-primary-900 text-2xl font-bold">{title}</h1>
+		<p class="text-primary-700 mt-2 text-sm">{description}</p>
+	</div>
+
+	{#if pageCount === 0}
+		<FileDropzone {onFilesSelected} />
+		<ToolError message={loadingError} class="mt-4" />
+	{:else}
+		<div class="space-y-4">
+			<FileDropzone
+				{onFilesSelected}
+				label="Anderes PDF ablegen"
+				sublabel={file?.name ?? ''}
+				class="py-4"
+			/>
+
+			<div class="flex flex-wrap items-center justify-between gap-3">
+				<h2 class="text-primary-900 text-lg font-semibold">
+					{file?.name} — {pageCount} Seite{pageCount === 1 ? '' : 'n'}
+				</h2>
+				<div class="flex flex-wrap gap-2">
+					{@render actions?.()}
+				</div>
+			</div>
+
+			{@render children()}
+
+			<ToolError message={error} />
+
+			<div class="flex items-center justify-between">
+				{@render footer()}
+			</div>
+		</div>
+	{/if}
+</div>

src/lib/components/ToolError.svelte

@@ -0,0 +1,20 @@
+<script lang="ts">
+	import { cn } from '$lib/utils';
+
+	type Props = {
+		/** German message; nothing is rendered when the value is empty. */
+		message?: string | null;
+		class?: string;
+	};
+
+	let { message, class: className = '' }: Props = $props();
+</script>
+
+{#if message}
+	<div
+		class={cn('rounded-lg border border-red-200 bg-red-50 p-4 text-sm text-red-800', className)}
+		role="alert"
+	>
+		{message}
+	</div>
+{/if}

src/lib/download.ts

@@ -1,19 +1,12 @@
-export const downloadBlob = (
+/**
-	bytes: Uint8Array,
+ * Copies PDF bytes into a tightly sized buffer before wrapping them in a Blob.
-	fileName: string,
+ * pdf-lib returns a `Uint8Array` that may be a view into a larger buffer, so the
-	mimeType: string = 'application/pdf'
+ * copy is required — one place decides this instead of every tool doing it.
-) => {
+ */
+export const pdfBytesToBlob = (bytes: Uint8Array, mimeType: string = 'application/pdf'): Blob => {
 	const buffer = new Uint8Array(bytes.byteLength);
 	buffer.set(bytes);
-	const blob = new Blob([buffer.buffer as ArrayBuffer], { type: mimeType });
+	return new Blob([buffer.buffer as ArrayBuffer], { type: mimeType });
-	const objectUrl = URL.createObjectURL(blob);
-	const downloadLink = document.createElement('a');
-
-	downloadLink.href = objectUrl;
-	downloadLink.download = fileName;
-	downloadLink.rel = 'noopener';
-	downloadLink.click();
-	window.setTimeout(() => URL.revokeObjectURL(objectUrl), 1000);
 };
 
 export const downloadBlobUrl = (blobUrl: string, fileName: string) => {
@@ -23,3 +16,16 @@ export const downloadBlobUrl = (blobUrl: string, fileName: string) => {
 	downloadLink.rel = 'noopener';
 	downloadLink.click();
 };
+
+/** Triggers a browser download for an existing Blob. */
+export const downloadBlobFile = (blob: Blob, fileName: string) => {
+	const objectUrl = URL.createObjectURL(blob);
+	downloadBlobUrl(objectUrl, fileName);
+	window.setTimeout(() => URL.revokeObjectURL(objectUrl), 1000);
+};
+
+export const downloadBlob = (
+	bytes: Uint8Array,
+	fileName: string,
+	mimeType: string = 'application/pdf'
+) => downloadBlobFile(pdfBytesToBlob(bytes, mimeType), fileName);

src/lib/exhibit-naming.ts

@@ -0,0 +1,73 @@
+/**
+ * Naming helpers for the exhibit numbering tool. Kept pure so the label the
+ * stamp draws and the file name the download gets can be tested without pdf-lib.
+ */
+
+/** Longest allowed exhibit designation (matches the input's `maxlength`). */
+export const MAX_EXHIBIT_PREFIX_LENGTH = 40;
+
+/** Designation used when the user leaves the field empty. */
+export const DEFAULT_EXHIBIT_PREFIX = 'Anlage';
+
+/** Characters that must never reach a file name on Windows, macOS or Linux. */
+const UNSAFE_FILE_NAME_CHARS = /[/\\:*?"<>|\u0000-\u001f]/g;
+
+export const MIN_EXHIBIT_START_NUMBER = 0;
+export const MAX_EXHIBIT_START_NUMBER = 99999;
+export const DEFAULT_EXHIBIT_START_NUMBER = 1;
+
+/**
+ * Clamps a typed start number. Empty or non-numeric input (a field being
+ * cleared) falls back to the default instead of producing `NaN` labels.
+ */
+export const normalizeExhibitStartNumber = (value: number | string | null | undefined): number => {
+	const parsed = Math.round(Number(value));
+	if (value === null || value === '' || !Number.isFinite(parsed)) {
+		return DEFAULT_EXHIBIT_START_NUMBER;
+	}
+
+	return Math.min(MAX_EXHIBIT_START_NUMBER, Math.max(MIN_EXHIBIT_START_NUMBER, parsed));
+};
+
+/** Trims and caps the designation; an empty result means "not filled in yet". */
+export const normalizeExhibitPrefix = (prefix: string): string =>
+	prefix.trim().slice(0, MAX_EXHIBIT_PREFIX_LENGTH);
+
+/**
+ * Stamp text: designation plus number with exactly one space and no leading
+ * zeros — `Anlage K 6`, never `Anlage K 06`.
+ */
+export const buildExhibitLabel = (prefix: string, number: number): string =>
+	`${normalizeExhibitPrefix(prefix)} ${number}`;
+
+/** File-name form of the designation: `Anlage K` → `Anlage_K`. */
+export const buildExhibitPrefixSlug = (prefix: string): string =>
+	normalizeExhibitPrefix(prefix).replace(/\s+/g, '_').replace(UNSAFE_FILE_NAME_CHARS, '') ||
+	DEFAULT_EXHIBIT_PREFIX;
+
+/**
+ * Zero-padding width: at least two digits, more when the highest assigned number
+ * needs them (1…99 → `06`, 1…100 → `006`).
+ */
+export const getExhibitNumberWidth = (highestNumber: number): number => {
+	const digits = Number.isFinite(highestNumber) ? String(Math.abs(highestNumber)).length : 1;
+	return Math.max(2, digits);
+};
+
+/**
+ * `{prefixSlug}_{paddedNumber}_{originalBase}.pdf` — the optional renaming
+ * described in the plan, e.g. `Anlage_K_06_Klageschrift.pdf`.
+ */
+export const buildExhibitFileName = (options: {
+	prefix: string;
+	number: number;
+	highestNumber: number;
+	originalName: string;
+}): string => {
+	const width = getExhibitNumberWidth(options.highestNumber);
+	const paddedNumber = String(options.number).padStart(width, '0');
+	const originalBase = options.originalName.replace(/\.pdf$/i, '');
+	const originalSlug = originalBase.replace(UNSAFE_FILE_NAME_CHARS, '') || 'Dokument';
+
+	return `${buildExhibitPrefixSlug(options.prefix)}_${paddedNumber}_${originalSlug}.pdf`;
+};

src/lib/latest-task.ts

@@ -0,0 +1,26 @@
+export type LatestToken = {
+	/** Starts a new operation and invalidates every earlier ticket. */
+	begin: () => number;
+	/** True while `ticket` is still the most recent `begin()`. */
+	isCurrent: (ticket: number) => boolean;
+	/** Invalidates the current ticket without starting a new operation. */
+	invalidate: () => void;
+};
+
+/**
+ * Guards async work so that only the most recent call may publish its result.
+ * Replaces the hand-rolled `generation`/`token` counters that every PDF route
+ * used to carry (stamp, pagination, page previews); late callers check
+ * `isCurrent` and clean up their own resources instead of writing stale state.
+ */
+export const createLatestToken = (): LatestToken => {
+	let current = 0;
+
+	return {
+		begin: () => (current += 1),
+		isCurrent: (ticket) => ticket === current,
+		invalidate: () => {
+			current += 1;
+		}
+	};
+};

src/lib/pdf-errors.ts

@@ -0,0 +1,66 @@
+const ENCRYPTED_PDF_PATTERN = /password|encrypted|encryption|verschl/i;
+
+/**
+ * Thrown by the overlay helpers for problems the user can fix (text too long,
+ * characters the standard font cannot encode). Callers render `message`
+ * directly instead of guessing from error text.
+ *
+ * Lives here rather than in `pdf-text-overlay.ts` so that tools which only need
+ * the error mapping do not pull pdf-lib into their bundle.
+ */
+export class TextOverlayError extends Error {
+	constructor(message: string) {
+		super(message);
+		this.name = 'TextOverlayError';
+	}
+}
+
+export type PdfErrorKind = 'encrypted' | 'text-overlay' | 'unknown';
+
+/**
+ * pdf-lib (`EncryptedPDFError`) and pdfjs (`PasswordException`) both surface
+ * password protection through the error name/message. Tools use this to show a
+ * single German hint instead of a generic failure.
+ */
+export const isEncryptedPdfError = (error: unknown): boolean => {
+	const message = error instanceof Error ? `${error.name} ${error.message}` : String(error);
+	return ENCRYPTED_PDF_PATTERN.test(message);
+};
+
+/**
+ * Classifies a PDF failure so routes can pick copy without matching on
+ * pdf-lib/pdfjs message text themselves.
+ */
+export const classifyPdfError = (error: unknown): PdfErrorKind => {
+	if (error instanceof TextOverlayError) return 'text-overlay';
+	if (isEncryptedPdfError(error)) return 'encrypted';
+	return 'unknown';
+};
+
+export const ENCRYPTED_PDF_MESSAGE =
+	'Dieses PDF ist passwortgeschützt. Entfernen Sie zuerst unter „Passwort entfernen“ den Schutz.';
+
+const GENERIC_LOAD_MESSAGE =
+	'PDF konnte nicht geladen werden. Prüfen Sie, ob die Datei gültig ist.';
+
+/**
+ * User-facing message for a failed PDF operation. Encryption and overlay errors
+ * keep their specific German copy; everything else falls back to `fallback`.
+ */
+export const pdfErrorMessage = (error: unknown, fallback: string): string => {
+	switch (classifyPdfError(error)) {
+		case 'encrypted':
+			return ENCRYPTED_PDF_MESSAGE;
+		case 'text-overlay':
+			return error instanceof Error ? error.message : fallback;
+		default:
+			return fallback;
+	}
+};
+
+export const pdfLoadErrorMessage = (error: unknown, fallback: string = GENERIC_LOAD_MESSAGE) =>
+	pdfErrorMessage(error, fallback);
+
+/** Shared row/banner message for PDFs that could not be transformed. */
+export const pdfProcessingErrorMessage = (error: unknown, fallback: string) =>
+	pdfErrorMessage(error, fallback);

src/lib/pdf-overlay.ts

@@ -11,13 +11,27 @@ export type OverlayPosition =
 
 export type WatermarkPosition = OverlayPosition | 'diagonal';
 
+/** Position choices shared by every tool that draws an overlay. */
+export const OVERLAY_POSITION_OPTIONS: { value: OverlayPosition; label: string }[] = [
+	{ value: 'top-left', label: 'Oben links' },
+	{ value: 'top-center', label: 'Oben mittig' },
+	{ value: 'top-right', label: 'Oben rechts' },
+	{ value: 'center', label: 'Zentriert' },
+	{ value: 'bottom-left', label: 'Unten links' },
+	{ value: 'bottom-center', label: 'Unten mittig' },
+	{ value: 'bottom-right', label: 'Unten rechts' }
+];
+
+/** Distance between a mark and the page edge used by the drawing helpers. */
+export const DEFAULT_OVERLAY_MARGIN = 20;
+
 export const getPositionCoords = (
 	pageWidth: number,
 	pageHeight: number,
 	markWidth: number,
 	markHeight: number,
 	position: WatermarkPosition,
-	margin = 20
+	margin = DEFAULT_OVERLAY_MARGIN
 ): { x: number; y: number } => {
 	const horizontallyCentered = (pageWidth - markWidth) / 2;
 
@@ -50,3 +64,26 @@ export const parseHexColor = (hexColor: string): RGB => {
 		Number.parseInt(match[3], 16) / 255
 	);
 };
+
+/** Inset used by the HTML previews to approximate the PDF margin at reading size. */
+export const PREVIEW_INSET = '5%';
+
+const PREVIEW_POSITION_STYLES: Record<OverlayPosition, Record<string, string>> = {
+	center: { left: '50%', top: '50%', transform: 'translate(-50%, -50%)' },
+	'top-left': { left: PREVIEW_INSET, top: PREVIEW_INSET },
+	'top-center': { left: '50%', top: PREVIEW_INSET, transform: 'translateX(-50%)' },
+	'top-right': { right: PREVIEW_INSET, top: PREVIEW_INSET },
+	'bottom-left': { bottom: PREVIEW_INSET, left: PREVIEW_INSET },
+	'bottom-center': { bottom: PREVIEW_INSET, left: '50%', transform: 'translateX(-50%)' },
+	'bottom-right': { bottom: PREVIEW_INSET, right: PREVIEW_INSET }
+};
+
+/** Declarative form, handy for `style:` directives or spreading into a style map. */
+export const getPreviewPositionStyles = (position: OverlayPosition): Record<string, string> =>
+	PREVIEW_POSITION_STYLES[position];
+
+/** Same styles as a single inline CSS string, for `style="…"` attributes. */
+export const getPreviewPositionStyle = (position: OverlayPosition): string =>
+	Object.entries(getPreviewPositionStyles(position))
+		.map(([property, value]) => `${property}: ${value};`)
+		.join(' ');

src/lib/pdf-pagination.ts

@@ -0,0 +1,111 @@
+import { PDFDocument, StandardFonts } from 'pdf-lib';
+import { parseHexColor, type OverlayPosition } from './pdf-overlay';
+import { drawTextOverlay } from './pdf-text-overlay';
+
+export const MIN_START_NUMBER = 1;
+export const MAX_START_NUMBER = 99999;
+export const PAGE_NUMBER_MARGIN = 28;
+export const PAGE_NUMBER_COLOR = '#1a1a1a';
+export const MIN_FONT_SIZE = 8;
+export const MAX_FONT_SIZE = 18;
+/** Longest allowed free text (Aktenzeichen) next to the sheet number. */
+export const MAX_FREE_TEXT_LENGTH = 60;
+
+const PAGINATION_PREFIXES = {
+	blatt: 'Bl. ',
+	seite: 'Seite ',
+	s: 'S. ',
+	nummer: ''
+} as const;
+
+export type PaginationFormat = keyof typeof PAGINATION_PREFIXES;
+
+/**
+ * Select options. The label is the rendered first sheet number (`Bl. 1`), so the
+ * UI cannot drift from the PDF text — there is no template syntax involved.
+ */
+export const PAGINATION_FORMATS: { value: PaginationFormat; label: string }[] = (
+	Object.keys(PAGINATION_PREFIXES) as PaginationFormat[]
+).map((value) => ({ value, label: `${PAGINATION_PREFIXES[value]}1`.trim() }));
+
+export type PaginationTextScope = 'all' | 'first';
+
+export type PaginationOptions = {
+	startNumber: number;
+	freeText: string;
+	textScope: PaginationTextScope;
+	format: PaginationFormat;
+	position: OverlayPosition;
+	fontSize: number;
+};
+
+type PaginationLabelOptions = Pick<
+	PaginationOptions,
+	'startNumber' | 'freeText' | 'textScope' | 'format'
+>;
+
+export const normalizeStartNumber = (value: number): number =>
+	Math.min(
+		MAX_START_NUMBER,
+		Math.max(MIN_START_NUMBER, Math.round(Number(value) || MIN_START_NUMBER))
+	);
+
+/** Trims the free text and enforces `MAX_FREE_TEXT_LENGTH` for programmatic callers. */
+export const normalizeFreeText = (value: string): string =>
+	value.trim().slice(0, MAX_FREE_TEXT_LENGTH);
+
+/**
+ * Sheet label for one page: `123 Ja 60/26, Bl. 27`. The number always appears —
+ * it is not user-removable — while the free text only appears on the first page
+ * when that scope is selected.
+ *
+ * Pure formatter: `startNumber` must already be normalised (see `paginatePdf`).
+ */
+export const buildPaginationLabel = (
+	pageIndex: number,
+	options: PaginationLabelOptions
+): string => {
+	const numberText = `${PAGINATION_PREFIXES[options.format]}${options.startNumber + pageIndex}`;
+	const freeText = options.freeText.trim();
+	const showsFreeText = options.textScope === 'all' || pageIndex === 0;
+
+	return showsFreeText && freeText ? `${freeText}, ${numberText}` : numberText;
+};
+
+/**
+ * Stamps every page with its ascending sheet number. Rotated scans are
+ * compensated so the number stays at the visual position.
+ *
+ * `MIN_FONT_SIZE` is the user's chosen floor: a label that does not fit even at
+ * that size raises a `TextOverlayError` instead of shrinking into illegibility.
+ */
+export const paginatePdf = async (
+	bytes: Uint8Array,
+	options: PaginationOptions
+): Promise<Uint8Array> => {
+	const document = await PDFDocument.load(bytes);
+	const font = await document.embedFont(StandardFonts.Helvetica);
+	const color = parseHexColor(PAGE_NUMBER_COLOR);
+	// Normalise once at the boundary so the formatter stays pure.
+	const labelOptions: PaginationLabelOptions = {
+		startNumber: normalizeStartNumber(options.startNumber),
+		freeText: normalizeFreeText(options.freeText),
+		textScope: options.textScope,
+		format: options.format
+	};
+
+	for (const [pageIndex, page] of document.getPages().entries()) {
+		drawTextOverlay(page, {
+			font,
+			text: buildPaginationLabel(pageIndex, labelOptions),
+			size: options.fontSize,
+			color,
+			position: options.position,
+			margin: PAGE_NUMBER_MARGIN,
+			minSize: MIN_FONT_SIZE,
+			compensatePageRotation: true
+		});
+	}
+
+	return document.save();
+};

src/lib/pdf-preview-text.ts

@@ -0,0 +1,57 @@
+let measureContext: CanvasRenderingContext2D | null | undefined;
+
+const getMeasureContext = () => {
+	if (measureContext !== undefined) return measureContext;
+
+	if (typeof document === 'undefined') {
+		measureContext = null;
+		return measureContext;
+	}
+
+	measureContext = document.createElement('canvas').getContext('2d');
+	return measureContext;
+};
+
+/** Rough average advance width per character, used when no canvas is available. */
+const FALLBACK_WIDTH_RATIO = 0.55;
+const LINE_HEIGHT_RATIO = 1.2;
+
+/**
+ * Approximate advance width of `text` in PDF points. The PDF standard font is
+ * Helvetica, and Arial/Liberation Sans are metrically compatible, so the
+ * browser's own text measurement is a good stand-in for the export.
+ */
+export const measureHelveticaText = (text: string, size: number): number => {
+	if (!text || size <= 0) return 0;
+
+	const context = getMeasureContext();
+	if (!context) return text.length * size * FALLBACK_WIDTH_RATIO;
+
+	context.font = `${size}px Helvetica, Arial, "Liberation Sans", sans-serif`;
+	return context.measureText(text).width;
+};
+
+/**
+ * Shrink factor (≤ 1) that the PDF export applies to keep a single line of text
+ * inside the available box. Lets the HTML preview mirror the export instead of
+ * clipping the label.
+ */
+export const getTextFitScale = (
+	text: string,
+	size: number,
+	availableWidth: number,
+	availableHeight: number
+): number => {
+	if (!text || size <= 0 || availableWidth <= 0) return 1;
+
+	const width = measureHelveticaText(text, size);
+	const fitsWidth = width <= availableWidth;
+	const fitsHeight = size * LINE_HEIGHT_RATIO <= availableHeight;
+
+	if (fitsWidth && fitsHeight) return 1;
+
+	const widthScale = width > 0 ? availableWidth / width : 1;
+	const heightScale = availableHeight / (size * LINE_HEIGHT_RATIO);
+
+	return Math.max(0, Math.min(1, widthScale, heightScale));
+};

src/lib/pdf-session.svelte.ts

@@ -0,0 +1,100 @@
+import { pdfLoadErrorMessage } from './pdf-errors';
+import { createLatestToken } from './latest-task';
+
+export type PdfSessionOptions<THandle> = {
+	/** Builds the tool-specific handle (thumbnails, page renderer, …). */
+	load: (file: File, bytes: Uint8Array) => Promise<THandle>;
+	/** Releases a handle that is replaced or cleared. */
+	dispose?: (handle: THandle) => void;
+	/** Resets tool state when a new file is picked (selections, previews, …). */
+	onFileChange?: () => void;
+	/** Fallback message when loading fails for a reason other than encryption. */
+	loadFallbackMessage?: string;
+};
+
+/**
+ * Shared single-PDF lifecycle: pick a file, read its bytes once, build a handle
+ * and map load errors to German copy. Replaces the per-route copies of
+ * `file`/`bytes`/`handle`/`isLoading`/`loadingError` plus their generation
+ * counters.
+ *
+ * Reads must go through the getters (`session.file`) so Svelte tracks them.
+ */
+export const createPdfSession = <THandle>(options: PdfSessionOptions<THandle>) => {
+	let file = $state<File | null>(null);
+	let bytes = $state<Uint8Array | null>(null);
+	let handle = $state<THandle | null>(null);
+	let isLoading = $state(false);
+	let loadingError = $state<string | null>(null);
+	const loadToken = createLatestToken();
+
+	const release = () => {
+		if (handle === null) return;
+		options.dispose?.(handle);
+		handle = null;
+	};
+
+	const load = async (nextFile: File) => {
+		const ticket = loadToken.begin();
+
+		release();
+		options.onFileChange?.();
+		file = nextFile;
+		bytes = null;
+		loadingError = null;
+		isLoading = true;
+
+		try {
+			const nextBytes = new Uint8Array(await nextFile.arrayBuffer());
+			const nextHandle = await options.load(nextFile, nextBytes);
+
+			if (!loadToken.isCurrent(ticket)) {
+				options.dispose?.(nextHandle);
+				return;
+			}
+
+			bytes = nextBytes;
+			handle = nextHandle;
+		} catch (error) {
+			console.error('Failed to load PDF:', error);
+			if (loadToken.isCurrent(ticket)) {
+				file = null;
+				loadingError = pdfLoadErrorMessage(error, options.loadFallbackMessage);
+			}
+		} finally {
+			if (loadToken.isCurrent(ticket)) isLoading = false;
+		}
+	};
+
+	/** Drops the current file and handle (used on unmount). */
+	const clear = () => {
+		loadToken.invalidate();
+		release();
+		file = null;
+		bytes = null;
+		loadingError = null;
+		isLoading = false;
+	};
+
+	return {
+		get file() {
+			return file;
+		},
+		get bytes() {
+			return bytes;
+		},
+		get handle() {
+			return handle;
+		},
+		get isLoading() {
+			return isLoading;
+		},
+		get loadingError() {
+			return loadingError;
+		},
+		load,
+		clear
+	};
+};
+
+export type PdfSession<THandle> = ReturnType<typeof createPdfSession<THandle>>;

src/lib/pdf-text-overlay.ts

@@ -0,0 +1,377 @@
+import { degrees, type PDFFont, type PDFImage, type PDFPage, type RGB } from 'pdf-lib';
+import { TextOverlayError } from './pdf-errors';
+import { getPositionCoords, type OverlayPosition } from './pdf-overlay';
+
+/** Default distance between an overlay mark and the page edge, in points. */
+export const TEXT_OVERLAY_MARGIN = 20;
+/** Default inner padding of a framed overlay mark, in points. */
+export const TEXT_OVERLAY_PADDING = 8;
+/** Default font-size floor while shrinking an overlay to fit the page. */
+export const MIN_TEXT_OVERLAY_SIZE = 4;
+export const TEXT_OVERLAY_BORDER_WIDTH = 2;
+/** Default height floor for image overlays, in points. */
+export const MIN_IMAGE_OVERLAY_SIZE = 20;
+
+/** Baseline nudge used by the framed text stamps so glyphs sit inside the border. */
+const BASELINE_OFFSET_RATIO = 0.2;
+const DEFAULT_TOO_LONG_MESSAGE =
+	'Der Text ist für mindestens eine Seite zu lang. Kürzen Sie den Text.';
+const TEXT_NOT_ENCODABLE_MESSAGE =
+	'Der Text enthält Zeichen, die nicht dargestellt werden können. Entfernen Sie z. B. Emoji.';
+
+export type TextOverlayOptions = {
+	font: PDFFont;
+	text: string;
+	/** Requested font size in points; shrunk down to `minSize` to fit the page. */
+	size: number;
+	color: RGB;
+	/** Where the mark sits on the *displayed* page (see `compensatePageRotation`). */
+	position: OverlayPosition;
+	/** Distance between the mark and the page edge in points. */
+	margin?: number;
+	/** Inner box padding; only used when `framed` is set. */
+	padding?: number;
+	framed?: boolean;
+	borderWidth?: number;
+	/** Additional counter-clockwise rotation of the mark in degrees. */
+	rotation?: number;
+	/** Font size floor while shrinking to fit the page. */
+	minSize?: number;
+	/**
+	 * Place the mark on rotated scans (`/Rotate 90`, `180`, `270`) where it is
+	 * visible instead of sideways. Opt-in so existing tools keep their output.
+	 * When enabled, `position` refers to the displayed page; otherwise it refers
+	 * to default user space.
+	 */
+	compensatePageRotation?: boolean;
+	tooLongMessage?: string;
+};
+
+export type ImageOverlayOptions = {
+	image: PDFImage;
+	/** Requested image height in points; scaled down (never up) to fit the page. */
+	size: number;
+	color: RGB;
+	position: OverlayPosition;
+	margin?: number;
+	/** Inner box padding; only used when `framed` is set. */
+	padding?: number;
+	framed?: boolean;
+	borderWidth?: number;
+	/** Additional counter-clockwise rotation of the mark in degrees. */
+	rotation?: number;
+	/** Height floor in points; smaller images are drawn at this height. */
+	minSize?: number;
+};
+
+type TextBox = {
+	size: number;
+	textHeight: number;
+	boxWidth: number;
+	boxHeight: number;
+};
+
+const measureText = (font: PDFFont, text: string, size: number) => {
+	try {
+		return { width: font.widthOfTextAtSize(text, size), height: font.heightAtSize(size) };
+	} catch (error) {
+		// The only expected failure here is a standard font that cannot encode a
+		// character. Anything else is a real bug and must not be reported to the
+		// user as an encoding problem.
+		if (error instanceof Error && /cannot encode|WinAnsi|StandardEncoding/i.test(error.message)) {
+			throw new TextOverlayError(TEXT_NOT_ENCODABLE_MESSAGE);
+		}
+
+		throw error;
+	}
+};
+
+type TextFitOptions = {
+	font: PDFFont;
+	text: string;
+	requestedSize: number;
+	/** Size of the displayed page after applying `/Rotate`. */
+	visualWidth: number;
+	visualHeight: number;
+	margin: number;
+	padding: number;
+	minSize: number;
+	tooLongMessage: string;
+};
+
+const fitTextToPage = ({
+	font,
+	text,
+	requestedSize,
+	visualWidth,
+	visualHeight,
+	margin,
+	padding,
+	minSize,
+	tooLongMessage
+}: TextFitOptions): TextBox => {
+	const availableWidth = visualWidth - margin * 2;
+	const availableHeight = visualHeight - margin * 2;
+	let size = requestedSize;
+	let metrics = measureText(font, text, size);
+
+	while (
+		size > minSize &&
+		(metrics.width + padding * 2 > availableWidth || metrics.height + padding * 2 > availableHeight)
+	) {
+		size = Math.max(minSize, size - 0.5);
+		metrics = measureText(font, text, size);
+	}
+
+	if (
+		metrics.width + padding * 2 > availableWidth ||
+		metrics.height + padding * 2 > availableHeight
+	) {
+		throw new TextOverlayError(tooLongMessage);
+	}
+
+	return {
+		size,
+		textHeight: metrics.height,
+		boxWidth: metrics.width + padding * 2,
+		boxHeight: metrics.height + padding * 2
+	};
+};
+
+/**
+ * Lower-left corner for a (possibly rotated) box inside the given page size.
+ * The bounding box of the rotated mark is aligned to the requested position, so
+ * tilted text never crosses the page edge.
+ */
+export const getRotatedBoxPlacement = (
+	pageWidth: number,
+	pageHeight: number,
+	boxWidth: number,
+	boxHeight: number,
+	position: OverlayPosition,
+	angle: number,
+	margin = TEXT_OVERLAY_MARGIN
+): { x: number; y: number } => {
+	const radians = (angle * Math.PI) / 180;
+	const cosine = Math.cos(radians);
+	const sine = Math.sin(radians);
+	const rotatedCorners = [
+		{ x: 0, y: 0 },
+		{ x: boxWidth * cosine, y: boxWidth * sine },
+		{ x: -boxHeight * sine, y: boxHeight * cosine },
+		{
+			x: boxWidth * cosine - boxHeight * sine,
+			y: boxWidth * sine + boxHeight * cosine
+		}
+	];
+	const minX = Math.min(...rotatedCorners.map((corner) => corner.x));
+	const maxX = Math.max(...rotatedCorners.map((corner) => corner.x));
+	const minY = Math.min(...rotatedCorners.map((corner) => corner.y));
+	const maxY = Math.max(...rotatedCorners.map((corner) => corner.y));
+	const boundingCoordinates = getPositionCoords(
+		pageWidth,
+		pageHeight,
+		maxX - minX,
+		maxY - minY,
+		position,
+		margin
+	);
+
+	return { x: boundingCoordinates.x - minX, y: boundingCoordinates.y - minY };
+};
+
+/** Normalised page rotation; anything that is not a multiple of 90 is ignored. */
+const getPageRotation = (page: PDFPage): number => {
+	const angle = Math.round(page.getRotation().angle / 90) * 90;
+	return ((angle % 360) + 360) % 360;
+};
+
+/** Displayed page size after applying `/Rotate`. */
+const getVisualPageSize = (pageWidth: number, pageHeight: number, pageRotation: number) =>
+	pageRotation % 180 === 0
+		? { width: pageWidth, height: pageHeight }
+		: { width: pageHeight, height: pageWidth };
+
+/**
+ * Maps a point on the displayed page back into default user space. Viewers
+ * rotate page content clockwise by `/Rotate`, so this is the inverse rotation
+ * that keeps a mark at the requested visual position.
+ *
+ * Invariant (covered by `tests/e2e/unit/pdf-text-overlay.spec.ts`): for every
+ * rotation, `toUserSpace` composed with the clockwise viewer rotation is the
+ * identity, i.e. the mark appears at the requested corner on screen.
+ */
+const toUserSpace = (
+	point: { x: number; y: number },
+	pageWidth: number,
+	pageHeight: number,
+	pageRotation: number
+) => {
+	switch (pageRotation) {
+		case 90:
+			return { x: pageWidth - point.y, y: point.x };
+		case 180:
+			return { x: pageWidth - point.x, y: pageHeight - point.y };
+		case 270:
+			return { x: point.y, y: pageHeight - point.x };
+		default:
+			return point;
+	}
+};
+
+/** Rotates an offset inside the mark box by `angle` around the box origin. */
+const rotateOffset = (offsetX: number, offsetY: number, angle: number) => {
+	const radians = (angle * Math.PI) / 180;
+	const cosine = Math.cos(radians);
+	const sine = Math.sin(radians);
+
+	return {
+		x: offsetX * cosine - offsetY * sine,
+		y: offsetX * sine + offsetY * cosine
+	};
+};
+
+/**
+ * Draws a single line of text (optionally framed) at one of the standard
+ * positions. Shrinks the font to fit the page and throws a `TextOverlayError`
+ * instead of clipping.
+ */
+export const drawTextOverlay = (page: PDFPage, options: TextOverlayOptions): void => {
+	const {
+		font,
+		text,
+		size,
+		color,
+		position,
+		margin = TEXT_OVERLAY_MARGIN,
+		padding = TEXT_OVERLAY_PADDING,
+		framed = false,
+		borderWidth = TEXT_OVERLAY_BORDER_WIDTH,
+		rotation = 0,
+		minSize = MIN_TEXT_OVERLAY_SIZE,
+		compensatePageRotation = false,
+		tooLongMessage = DEFAULT_TOO_LONG_MESSAGE
+	} = options;
+
+	const boxPadding = framed ? padding : 0;
+	const { width, height } = page.getSize();
+	const pageRotation = compensatePageRotation ? getPageRotation(page) : 0;
+	const visual = getVisualPageSize(width, height, pageRotation);
+	const box = fitTextToPage({
+		font,
+		text,
+		requestedSize: size,
+		visualWidth: visual.width,
+		visualHeight: visual.height,
+		margin,
+		padding: boxPadding,
+		minSize,
+		tooLongMessage
+	});
+	const placement = getRotatedBoxPlacement(
+		visual.width,
+		visual.height,
+		box.boxWidth,
+		box.boxHeight,
+		position,
+		rotation,
+		margin
+	);
+	const origin = toUserSpace(placement, width, height, pageRotation);
+	const angle = rotation + pageRotation;
+	const textOffset = rotateOffset(
+		boxPadding,
+		boxPadding + box.textHeight * BASELINE_OFFSET_RATIO,
+		angle
+	);
+
+	if (framed) {
+		page.drawRectangle({
+			x: origin.x,
+			y: origin.y,
+			width: box.boxWidth,
+			height: box.boxHeight,
+			borderColor: color,
+			borderWidth,
+			rotate: degrees(angle)
+		});
+	}
+
+	page.drawText(text, {
+		x: origin.x + textOffset.x,
+		y: origin.y + textOffset.y,
+		size: box.size,
+		font,
+		color,
+		rotate: degrees(angle)
+	});
+};
+
+/**
+ * Draws an image (optionally framed) at one of the standard positions, scaled
+ * down to fit the page. Kept next to `drawTextOverlay` so the rotated-placement
+ * maths lives in one place instead of being repeated in a route.
+ */
+export const drawImageOverlay = (page: PDFPage, options: ImageOverlayOptions): void => {
+	const {
+		image,
+		size,
+		color,
+		position,
+		margin = TEXT_OVERLAY_MARGIN,
+		padding = TEXT_OVERLAY_PADDING,
+		framed = false,
+		borderWidth = TEXT_OVERLAY_BORDER_WIDTH,
+		rotation = 0,
+		minSize = MIN_IMAGE_OVERLAY_SIZE
+	} = options;
+
+	const boxPadding = framed ? padding : 0;
+	const { width, height } = page.getSize();
+	const aspectRatio = image.width / image.height;
+	let drawHeight = size;
+	let drawWidth = drawHeight * aspectRatio;
+
+	const availableWidth = width - margin * 2 - boxPadding * 2;
+	const availableHeight = height - margin * 2 - boxPadding * 2;
+	if (drawWidth > availableWidth || drawHeight > availableHeight) {
+		const scale = Math.min(availableWidth / drawWidth, availableHeight / drawHeight);
+		drawWidth *= scale;
+		drawHeight *= scale;
+	}
+	if (drawHeight < minSize) {
+		drawHeight = minSize;
+		drawWidth = drawHeight * aspectRatio;
+	}
+
+	const placement = getRotatedBoxPlacement(
+		width,
+		height,
+		drawWidth + boxPadding * 2,
+		drawHeight + boxPadding * 2,
+		position,
+		rotation,
+		margin
+	);
+
+	if (framed) {
+		page.drawRectangle({
+			x: placement.x,
+			y: placement.y,
+			width: drawWidth + boxPadding * 2,
+			height: drawHeight + boxPadding * 2,
+			borderColor: color,
+			borderWidth,
+			rotate: degrees(rotation)
+		});
+	}
+
+	const imageOffset = rotateOffset(boxPadding, boxPadding, rotation);
+	page.drawImage(image, {
+		x: placement.x + imageOffset.x,
+		y: placement.y + imageOffset.y,
+		width: drawWidth,
+		height: drawHeight,
+		rotate: degrees(rotation)
+	});
+};

src/lib/pdf-thumbnails.ts

@@ -1,17 +1,48 @@
-export type PdfThumbnail = {
+import type { PDFPageProxy } from 'pdfjs-dist';
+
+import { createLatestToken } from './latest-task';
+
+/** One rasterised page, used for thumbnails and for on-demand previews. */
+export type PdfPageImage = {
 	pageNumber: number;
 	imageUrl: string;
 	width: number;
 	height: number;
 };
 
+/** Thumbnail grids and on-demand previews share one page-image shape. */
+export type PdfThumbnail = PdfPageImage;
+
 export type PdfDocumentHandle = {
 	pageCount: number;
-	thumbnails: PdfThumbnail[];
+	thumbnails: PdfPageImage[];
 	destroy: () => void;
 };
 
-export async function loadPdfDocument(data: Uint8Array): Promise<PdfDocumentHandle> {
+/** Pixel scale used for on-demand page previews. */
+export const PDF_PREVIEW_SCALE = 1.25;
+/** Pixel scale used for the page grid thumbnails. */
+export const PDF_THUMBNAIL_SCALE = 0.5;
+
+/** Thrown when a render was superseded by a newer one or by unmounting. */
+export class PreviewRenderCancelledError extends Error {
+	constructor(message = 'Die PDF-Vorschau wurde zwischenzeitlich geändert.') {
+		super(message);
+		this.name = 'PreviewRenderCancelledError';
+	}
+}
+
+/**
+ * Renders one page at a time. Used by tools that operate on a whole document
+ * (pagination) where rasterising every page up front would exhaust memory.
+ */
+export type PdfPageRenderer = {
+	pageCount: number;
+	render: (pageNumber: number) => Promise<PdfPageImage>;
+	destroy: () => void;
+};
+
+const loadPdfJs = async () => {
 	const pdfjsLib = await import('pdfjs-dist');
 	const { getDocument, GlobalWorkerOptions } = pdfjsLib;
 
@@ -19,36 +50,55 @@ export async function loadPdfDocument(data: Uint8Array): Promise<PdfDocumentHand
 		(module) => module.default
 	);
 
+	return getDocument;
+};
+
+const canvasToPngBlob = (canvas: HTMLCanvasElement) =>
+	new Promise<Blob>((resolve, reject) => {
+		canvas.toBlob(
+			(result) => (result ? resolve(result) : reject(new Error('Could not encode PDF thumbnail.'))),
+			'image/png'
+		);
+	});
+
+/**
+ * Rasterises a single page and returns an object URL for the PNG. Shared by the
+ * thumbnail grid and the on-demand preview renderer so both stay in sync.
+ */
+const renderPageToPngUrl = async (page: PDFPageProxy, scale: number) => {
+	const viewport = page.getViewport({ scale });
+	const canvas = document.createElement('canvas');
+	canvas.width = Math.ceil(viewport.width);
+	canvas.height = Math.ceil(viewport.height);
+	const canvasContext = canvas.getContext('2d');
+
+	if (!canvasContext) throw new Error('Could not create a canvas for the PDF page.');
+
+	await page.render({ canvas, canvasContext, viewport }).promise;
+
+	return {
+		imageUrl: URL.createObjectURL(await canvasToPngBlob(canvas)),
+		width: viewport.width,
+		height: viewport.height
+	};
+};
+
+export async function loadPdfDocument(data: Uint8Array): Promise<PdfDocumentHandle> {
+	const getDocument = await loadPdfJs();
+
+	// pdfjs transfers the buffer to its worker, so it always gets its own copy —
+	// callers keep using `data` for the export.
 	const loadingTask = getDocument({ data: new Uint8Array(data) });
-	const thumbnails: PdfThumbnail[] = [];
+	const thumbnails: PdfPageImage[] = [];
 
 	try {
 		const pdfDocument = await loadingTask.promise;
 
 		for (let pageNumber = 1; pageNumber <= pdfDocument.numPages; pageNumber += 1) {
 			const page = await pdfDocument.getPage(pageNumber);
-			const viewport = page.getViewport({ scale: 0.5 });
-			const canvas = document.createElement('canvas');
-			canvas.width = Math.ceil(viewport.width);
-			canvas.height = Math.ceil(viewport.height);
-			const canvasContext = canvas.getContext('2d');
-
-			if (!canvasContext) throw new Error('Could not create thumbnail canvas context.');
-
-			await page.render({ canvas, canvasContext, viewport }).promise;
-			const blob = await new Promise<Blob>((resolve, reject) => {
-				canvas.toBlob(
-					(result) =>
-						result ? resolve(result) : reject(new Error('Could not encode PDF thumbnail.')),
-					'image/png'
-				);
-			});
-
 			thumbnails.push({
 				pageNumber,
-				imageUrl: URL.createObjectURL(blob),
+				...(await renderPageToPngUrl(page, PDF_THUMBNAIL_SCALE))
-				width: viewport.width,
-				height: viewport.height
 			});
 		}
 
@@ -69,3 +119,62 @@ export async function loadPdfDocument(data: Uint8Array): Promise<PdfDocumentHand
 		throw error;
 	}
 }
+
+export async function loadPdfPageRenderer(data: Uint8Array): Promise<PdfPageRenderer> {
+	const getDocument = await loadPdfJs();
+
+	const loadingTask = getDocument({ data: new Uint8Array(data) });
+	let pdfDocument;
+
+	try {
+		pdfDocument = await loadingTask.promise;
+	} catch (error) {
+		// Mirror `loadPdfDocument`: a failed load must not leave the worker and its
+		// copy of the document data alive.
+		await loadingTask.destroy();
+		throw error;
+	}
+
+	let destroyed = false;
+	let currentUrl: string | null = null;
+	const renderToken = createLatestToken();
+
+	const releaseUrl = () => {
+		if (currentUrl) URL.revokeObjectURL(currentUrl);
+		currentUrl = null;
+	};
+
+	return {
+		pageCount: pdfDocument.numPages,
+		render: async (pageNumber) => {
+			if (destroyed) throw new PreviewRenderCancelledError('Die PDF-Vorschau wurde geschlossen.');
+
+			const token = renderToken.begin();
+			const clampedPage = Math.min(
+				pdfDocument.numPages,
+				Math.max(1, Math.round(Number(pageNumber) || 1))
+			);
+			const page = await pdfDocument.getPage(clampedPage);
+			const rendered = await renderPageToPngUrl(page, PDF_PREVIEW_SCALE);
+
+			// A newer render (or unmount) superseded this one: drop the bitmap
+			// instead of leaving an orphaned object URL behind.
+			if (destroyed || !renderToken.isCurrent(token)) {
+				URL.revokeObjectURL(rendered.imageUrl);
+				throw new PreviewRenderCancelledError();
+			}
+
+			releaseUrl();
+			currentUrl = rendered.imageUrl;
+
+			return { pageNumber: clampedPage, ...rendered };
+		},
+		destroy: () => {
+			if (destroyed) return;
+			destroyed = true;
+			renderToken.invalidate();
+			releaseUrl();
+			void loadingTask.destroy();
+		}
+	};
+}

src/lib/pending-files.ts

@@ -1,11 +1,37 @@
-let pendingZipFiles: File[] = [];
+/** Routes that can receive a handoff from another route. */
+export type PendingFileTarget = 'bea' | 'pagination';
 
-export const queueZipFiles = (files: File[]) => {
+type QueuedFile = { file: File; target: PendingFileTarget };
-	pendingZipFiles = [...pendingZipFiles, ...files];
+
+let queue: QueuedFile[] = [];
+
+/**
+ * In-memory handoff between routes (start page → beA workspace, merge →
+ * pagination). Nothing is uploaded or persisted; the receiving route takes and
+ * clears the files queued for its own target on mount.
+ *
+ * The target keeps a queued ZIP from being consumed — and silently dropped — by
+ * a tool that only accepts PDFs.
+ */
+export const queuePendingFiles = (files: File[], target: PendingFileTarget) => {
+	queue = [...queue, ...files.map((file) => ({ file, target }))];
 };
 
-export const takeQueuedZipFiles = () => {
+/** Takes (and clears) the files queued for `target`; other targets stay queued. */
-	const files = pendingZipFiles;
+export const takePendingFiles = (target: PendingFileTarget): File[] => {
-	pendingZipFiles = [];
+	const taken: File[] = [];
-	return files;
+	const remaining: QueuedFile[] = [];
+
+	for (const entry of queue) {
+		if (entry.target === target) taken.push(entry.file);
+		else remaining.push(entry);
+	}
+
+	queue = remaining;
+	return taken;
+};
+
+/** Test/storybook helper: forget everything that is still queued. */
+export const clearPendingFiles = () => {
+	queue = [];
 };

src/lib/tools.ts

@@ -12,6 +12,19 @@ export const tools: Tool[] = [
 		description: 'Versehen Sie Seiten mit Textstempeln wie „Beglaubigt“ oder „Eilt“.',
 		icon: 'stamp'
 	},
+	{
+		slug: 'pagination',
+		title: 'Paginieren',
+		description:
+			'Versehen Sie alle Seiten mit fortlaufenden Blattnummern und optional einem Aktenzeichen.',
+		icon: 'list-ordered'
+	},
+	{
+		slug: 'exhibits',
+		title: 'Anlagen nummerieren',
+		description: 'Nummerieren und benennen Sie Anlagen für die Einreichung — mit Anlagenstempel.',
+		icon: 'files'
+	},
 	{
 		slug: 'watermark',
 		title: 'Wasserzeichen',

src/routes/+page.svelte

@@ -9,6 +9,8 @@
 		Scissors,
 		Merge,
 		Stamp,
+		ListOrdered,
+		Files,
 		RotateCw,
 		Info,
 		FileText
@@ -16,7 +18,7 @@
 	import { goto } from '$app/navigation';
 	import FileDropzone from '$lib/components/FileDropzone.svelte';
 	import * as Card from '$lib/components/ui/card/index';
-	import { queueZipFiles } from '$lib/pending-files';
+	import { queuePendingFiles } from '$lib/pending-files';
 	import { isAcceptedWorkspaceFile, WORKSPACE_ACCEPT_TYPES } from '$lib/zip-selection';
 	import { tools } from '$lib/tools';
 
@@ -29,6 +31,8 @@
 		scissors: Scissors,
 		merge: Merge,
 		stamp: Stamp,
+		'list-ordered': ListOrdered,
+		files: Files,
 		'rotate-cw': RotateCw,
 		info: Info
 	};
@@ -37,7 +41,7 @@
 		const workspaceFiles = files.filter(isAcceptedWorkspaceFile);
 		if (workspaceFiles.length === 0) return;
 
-		queueZipFiles(workspaceFiles);
+		queuePendingFiles(workspaceFiles, 'bea');
 		void goto('/tools/bea');
 	};
 
@@ -62,12 +66,12 @@
 <div class="flex flex-col gap-10 px-4 py-10">
 	<!-- Hero -->
 	<div class="flex flex-col items-center gap-2 text-center">
-		<h1 class="text-[28px] font-bold text-primary-900">Werkzeugkasten für beA</h1>
+		<h1 class="text-primary-900 text-[28px] font-bold">Werkzeugkasten für beA</h1>
-		<p class="max-w-lg text-[15px] font-medium text-primary-700">
+		<p class="text-primary-700 max-w-lg text-[15px] font-medium">
 			Bereiten Sie ZIP-Archive aus dem besonderen elektronischen Anwaltspostfach (beA) auf — plus
 			praktische PDF-Werkzeuge.
 		</p>
-		<p class="max-w-lg text-[13px] text-primary-700">
+		<p class="text-primary-700 max-w-lg text-[13px]">
 			Alle Werkzeuge laufen zu 100 % in Ihrem Browser — keine Dateien werden hochgeladen.
 		</p>
 	</div>
@@ -84,7 +88,7 @@
 			icon={Archive}
 			class="py-10"
 		/>
-		<p class="mt-2 text-center text-[12px] text-primary-600">
+		<p class="text-primary-600 mt-2 text-center text-[12px]">
 			Tipp: In beA exportierte Archive enden auf .zip und enthalten Ihre Anlagen als PDF. PDFs
 			können direkt in Teildokumente aufgeteilt werden.
 		</p>
@@ -92,12 +96,12 @@
 
 	<!-- Tool grid -->
 	<div class="mx-auto w-full max-w-4xl">
-		<h2 class="mb-4 text-[18px] font-bold text-primary-900">Weitere PDF-Werkzeuge</h2>
+		<h2 class="text-primary-900 mb-4 text-[18px] font-bold">Weitere PDF-Werkzeuge</h2>
 		<div class="grid grid-cols-1 gap-4 sm:grid-cols-2 lg:grid-cols-3">
 			{#each tools as tool}
 				{@const Icon = iconMap[tool.icon] ?? FileText}
 				<a href="/tools/{tool.slug}" class="block">
-					<Card.Root class="h-full transition hover:shadow-md cursor-pointer">
+					<Card.Root class="h-full cursor-pointer transition hover:shadow-md">
 						<Card.Content class="flex flex-col gap-3 py-6">
 							<div
 								class="flex h-10 w-10 items-center justify-center rounded-xl bg-primary/10 text-primary"
@@ -105,8 +109,8 @@
 								<Icon class="h-5 w-5" />
 							</div>
 							<div>
-								<h3 class="text-[15px] font-bold text-primary-900">{tool.title}</h3>
+								<h3 class="text-primary-900 text-[15px] font-bold">{tool.title}</h3>
-								<p class="mt-1 text-[13px] leading-snug text-primary-700">{tool.description}</p>
+								<p class="text-primary-700 mt-1 text-[13px] leading-snug">{tool.description}</p>
 							</div>
 						</Card.Content>
 					</Card.Root>

src/routes/tools/bea/+page.svelte

@@ -14,7 +14,7 @@
 	} from '$lib/zip-processing';
 	import { isAcceptedPdfFile } from '$lib/zip-selection';
 	import { downloadBlob } from '$lib/download';
-	import { takeQueuedZipFiles } from '$lib/pending-files';
+	import { takePendingFiles } from '$lib/pending-files';
 	import * as Card from '$lib/components/ui/card/index';
 
 	const THUMBNAIL_WIDTH_STORAGE_KEY = 'thumbnailWidth';
@@ -43,7 +43,7 @@
 
 		thumbnailWidthHydrated = true;
 
-		const queuedFiles = takeQueuedZipFiles();
+		const queuedFiles = takePendingFiles('bea');
 		if (queuedFiles.length > 0) handleFilesSelected(queuedFiles);
 	});
 
@@ -201,6 +201,6 @@
 {/snippet}
 
 <div>
-	<h1 class="h1 text-[20px] font-bold text-primary-900">beA-Edit</h1>
+	<h1 class="h1 text-primary-900 text-[20px] font-bold">beA-Edit</h1>
 	{@render content()}
 </div>

src/routes/tools/compress/+page.svelte

@@ -4,6 +4,7 @@
 	import Button from '$lib/components/ui/button.svelte';
 	import { createBatchItem, runBatch, type BatchItem } from '$lib/batch';
 	import { downloadBlob } from '$lib/download';
+	import { pdfProcessingErrorMessage } from '$lib/pdf-errors';
 	import {
 		compressWithPreset,
 		compressionPresets,
@@ -12,6 +13,9 @@
 	import { isRasterizationTooLarge, RASTERIZATION_MAX_BYTES } from '$lib/rasterization-limits';
 	import { AlertTriangle } from '@lucide/svelte';
 
+	const compressErrorMessage = (error: unknown) =>
+		pdfProcessingErrorMessage(error, 'Diese PDF konnte nicht komprimiert werden.');
+
 	let items = $state<BatchItem[]>([]);
 	let selectedPreset = $state(defaultCompressionPreset.id);
 	let isRunning = $state(false);
@@ -55,7 +59,7 @@
 		isRunning = true;
 		try {
 			await runBatch(queue, processFile, updateItem, {
-				errorMessage: 'Diese PDF konnte nicht komprimiert werden.',
+				errorMessage: compressErrorMessage,
 				// Skip rows removed while they were still waiting in the queue.
 				shouldProcess: (id) => items.some((item) => item.id === id)
 			});
@@ -72,7 +76,7 @@
 		isRunning = true;
 		try {
 			await runBatch([item], processFile, updateItem, {
-				errorMessage: 'Diese PDF konnte nicht komprimiert werden.'
+				errorMessage: compressErrorMessage
 			});
 		} finally {
 			isRunning = false;
@@ -97,8 +101,8 @@
 		</p>
 	</div>
 
-	<div class="rounded-lg border border-amber-200 bg-amber-50 p-4 flex gap-3">
+	<div class="flex gap-3 rounded-lg border border-amber-200 bg-amber-50 p-4">
-		<AlertTriangle class="h-5 w-5 shrink-0 text-amber-600 mt-0.5" />
+		<AlertTriangle class="mt-0.5 h-5 w-5 shrink-0 text-amber-600" />
 		<div class="text-sm text-amber-800">
 			<p class="font-medium">Hinweis zur Qualität</p>
 			<p class="mt-1">
@@ -118,17 +122,17 @@
 	/>
 
 	{#if items.length > 0}
-		<div class="rounded-2xl border border-border bg-card p-4 space-y-4">
+		<div class="space-y-4 rounded-2xl border border-border bg-card p-4">
 			<h2 class="text-lg font-semibold text-foreground">Komprimierungsstufe</h2>
 			<p class="text-xs text-primary">Die Einstellung gilt für alle Dateien der Liste.</p>
 
 			<div class="space-y-2">
 				{#each compressionPresets as preset (preset.id)}
 					<label
-						class="flex items-start gap-3 rounded-lg border p-3 cursor-pointer transition {selectedPreset ===
+						class="flex cursor-pointer items-start gap-3 rounded-lg border p-3 transition {selectedPreset ===
 						preset.id
 							? 'border-primary bg-primary/5'
-							: 'border-border hover:border-primary-300'}"
+							: 'hover:border-primary-300 border-border'}"
 					>
 						<input
 							type="radio"

src/routes/tools/convert/+page.svelte

@@ -1,8 +1,10 @@
 <script lang="ts">
 	import FileDropzone from '$lib/components/FileDropzone.svelte';
 	import RasterizationWarning from '$lib/components/RasterizationWarning.svelte';
+	import ToolError from '$lib/components/ToolError.svelte';
 	import Button from '$lib/components/ui/button.svelte';
 	import { downloadBlob, downloadBlobUrl } from '$lib/download';
+	import { pdfProcessingErrorMessage } from '$lib/pdf-errors';
 	import { isRasterizationTooLarge } from '$lib/rasterization-limits';
 	import { zipSync } from 'fflate';
 	import { Image } from '@lucide/svelte';
@@ -92,7 +94,7 @@
 			}
 		} catch (conversionError) {
 			console.error('Conversion failed:', conversionError);
-			error = 'Fehler beim Konvertieren des PDFs.';
+			error = pdfProcessingErrorMessage(conversionError, 'Fehler beim Konvertieren des PDFs.');
 		} finally {
 			isProcessing = false;
 		}
@@ -101,8 +103,8 @@
 
 <div class="mx-auto max-w-4xl space-y-6">
 	<div>
-		<h1 class="text-2xl font-bold text-primary-900">Konvertieren</h1>
+		<h1 class="text-primary-900 text-2xl font-bold">Konvertieren</h1>
-		<p class="mt-2 text-sm text-primary-700">Konvertieren Sie ein PDF in Bilder (PNG oder JPEG).</p>
+		<p class="text-primary-700 mt-2 text-sm">Konvertieren Sie ein PDF in Bilder (PNG oder JPEG).</p>
 	</div>
 
 	{#if !pdfFile}
@@ -116,28 +118,28 @@
 				class="py-4"
 			/>
 			<RasterizationWarning file={pdfFile} />
-			<div class="rounded-xl border border-primary-200 bg-white p-4 space-y-4">
+			<div class="border-primary-200 space-y-4 rounded-xl border bg-white p-4">
-				<div class="flex items-center gap-2 text-primary-900">
+				<div class="text-primary-900 flex items-center gap-2">
 					<Image class="h-5 w-5" />
 					<h2 class="text-lg font-semibold">{pdfFile.name}</h2>
 				</div>
 
 				<div>
-					<p class="text-sm font-medium text-primary-900 mb-2">Bildformat</p>
+					<p class="text-primary-900 mb-2 text-sm font-medium">Bildformat</p>
 					<div class="flex gap-3">
-						<label class="flex items-center gap-2 cursor-pointer">
+						<label class="flex cursor-pointer items-center gap-2">
 							<input type="radio" bind:group={outputFormat} value="png" class="h-4 w-4" />
-							<span class="text-sm text-primary-700">PNG (verlustfrei)</span>
+							<span class="text-primary-700 text-sm">PNG (verlustfrei)</span>
 						</label>
-						<label class="flex items-center gap-2 cursor-pointer">
+						<label class="flex cursor-pointer items-center gap-2">
 							<input type="radio" bind:group={outputFormat} value="jpeg" class="h-4 w-4" />
-							<span class="text-sm text-primary-700">JPEG (kleiner)</span>
+							<span class="text-primary-700 text-sm">JPEG (kleiner)</span>
 						</label>
 					</div>
 				</div>
 
 				<div>
-					<label class="block text-sm font-medium text-primary-900 mb-1" for="render-scale">
+					<label class="text-primary-900 mb-1 block text-sm font-medium" for="render-scale">
 						Auflösung: {scale}x
 					</label>
 					<input
@@ -149,7 +151,7 @@
 						bind:value={scale}
 						class="w-full"
 					/>
-					<p class="text-xs text-primary-600 mt-1">
+					<p class="text-primary-600 mt-1 text-xs">
 						{scale === 1
 							? '~72 DPI'
 							: scale === 2
@@ -162,11 +164,11 @@
 
 				{#if isProcessing && totalPages > 0}
 					<div class="space-y-1">
-						<div class="flex justify-between text-xs text-primary-700">
+						<div class="text-primary-700 flex justify-between text-xs">
 							<span>Wird konvertiert...</span>
 							<span>{progress} / {totalPages}</span>
 						</div>
-						<div class="h-2 w-full rounded-full bg-primary-100">
+						<div class="bg-primary-100 h-2 w-full rounded-full">
 							<div
 								class="h-2 rounded-full bg-primary transition-all"
 								style="width: {(progress / totalPages) * 100}%"
@@ -176,11 +178,7 @@
 				{/if}
 			</div>
 
-			{#if error}
+			<ToolError message={error} />
-				<div class="rounded-lg border border-red-200 bg-red-50 p-4 text-sm text-red-800">
-					{error}
-				</div>
-			{/if}
 
 			<div class="flex justify-end gap-2">
 				<Button onclick={convertPdf} disabled={isProcessing || rasterizationBlocked}>

src/routes/tools/decrypt/+page.svelte

@@ -2,6 +2,7 @@
 	import { PDFDocument } from 'pdf-lib';
 	import BatchFileList from '$lib/components/BatchFileList.svelte';
 	import FileDropzone from '$lib/components/FileDropzone.svelte';
+	import ToolError from '$lib/components/ToolError.svelte';
 	import Button from '$lib/components/ui/button.svelte';
 	import { createBatchItem, runBatch, type BatchItem } from '$lib/batch';
 	import { downloadBlob } from '$lib/download';
@@ -142,8 +143,8 @@
 		</p>
 	</div>
 
-	<div class="rounded-lg border border-amber-200 bg-amber-50 p-4 flex gap-3">
+	<div class="flex gap-3 rounded-lg border border-amber-200 bg-amber-50 p-4">
-		<AlertTriangle class="h-5 w-5 shrink-0 text-amber-600 mt-0.5" />
+		<AlertTriangle class="mt-0.5 h-5 w-5 shrink-0 text-amber-600" />
 		<div class="text-sm text-amber-800">
 			<p class="font-medium">Hinweis zur Qualität</p>
 			<p class="mt-1">
@@ -163,7 +164,7 @@
 	/>
 
 	{#if items.length > 0}
-		<div class="rounded-2xl border border-border bg-card p-4 space-y-4">
+		<div class="space-y-4 rounded-2xl border border-border bg-card p-4">
 			<div class="flex items-center gap-2 text-foreground">
 				<Unlock class="h-5 w-5" />
 				<h2 class="text-lg font-semibold">Passwort</h2>
@@ -171,14 +172,14 @@
 			<p class="text-xs text-primary">Das Passwort gilt für alle Dateien der Liste.</p>
 
 			<div>
-				<label class="block text-sm font-medium text-foreground mb-1" for="decrypt-password">
+				<label class="mb-1 block text-sm font-medium text-foreground" for="decrypt-password">
 					Passwort
 				</label>
 				<input
 					id="decrypt-password"
 					type="password"
 					bind:value={password}
-					class="w-full rounded-lg border border-border px-3 py-2 text-sm focus:border-primary focus:outline-none focus:ring-1 focus:ring-primary"
+					class="w-full rounded-lg border border-border px-3 py-2 text-sm focus:border-primary focus:ring-1 focus:ring-primary focus:outline-none"
 					placeholder="Passwort der PDFs eingeben"
 				/>
 			</div>
@@ -199,11 +200,7 @@
 		/>
 	{/if}
 
-	{#if error}
+	<ToolError message={error} />
-		<div class="rounded-lg border border-red-200 bg-red-50 p-4 text-sm text-red-800">
-			{error}
-		</div>
-	{/if}
 
 	{#if items.length > 0}
 		<div class="flex justify-end">

src/routes/tools/encrypt/+page.svelte

@@ -2,6 +2,7 @@
 	import { PDFDocument } from '@cantoo/pdf-lib';
 	import BatchFileList from '$lib/components/BatchFileList.svelte';
 	import FileDropzone from '$lib/components/FileDropzone.svelte';
+	import ToolError from '$lib/components/ToolError.svelte';
 	import Button from '$lib/components/ui/button.svelte';
 	import { createBatchItem, runBatch, type BatchItem } from '$lib/batch';
 	import { downloadBlob } from '$lib/download';
@@ -112,7 +113,7 @@
 	/>
 
 	{#if items.length > 0}
-		<div class="rounded-2xl border border-border bg-card p-4 space-y-4">
+		<div class="space-y-4 rounded-2xl border border-border bg-card p-4">
 			<div class="flex items-center gap-2 text-foreground">
 				<Lock class="h-5 w-5" />
 				<h2 class="text-lg font-semibold">Passwort</h2>
@@ -120,21 +121,21 @@
 			<p class="text-xs text-primary">Das Passwort gilt für alle Dateien der Liste.</p>
 
 			<div>
-				<label class="block text-sm font-medium text-foreground mb-1" for="encrypt-password">
+				<label class="mb-1 block text-sm font-medium text-foreground" for="encrypt-password">
 					Passwort
 				</label>
 				<input
 					id="encrypt-password"
 					type="password"
 					bind:value={password}
-					class="w-full rounded-lg border border-border px-3 py-2 text-sm focus:border-primary focus:outline-none focus:ring-1 focus:ring-primary"
+					class="w-full rounded-lg border border-border px-3 py-2 text-sm focus:border-primary focus:ring-1 focus:ring-primary focus:outline-none"
 					placeholder="Passwort eingeben"
 				/>
 			</div>
 
 			<div>
 				<label
-					class="block text-sm font-medium text-foreground mb-1"
+					class="mb-1 block text-sm font-medium text-foreground"
 					for="encrypt-password-confirmation"
 				>
 					Passwort bestätigen
@@ -143,7 +144,7 @@
 					id="encrypt-password-confirmation"
 					type="password"
 					bind:value={confirmPassword}
-					class="w-full rounded-lg border border-border px-3 py-2 text-sm focus:border-primary focus:outline-none focus:ring-1 focus:ring-primary"
+					class="w-full rounded-lg border border-border px-3 py-2 text-sm focus:border-primary focus:ring-1 focus:ring-primary focus:outline-none"
 					placeholder="Passwort wiederholen"
 				/>
 			</div>
@@ -176,11 +177,7 @@
 		/>
 	{/if}
 
-	{#if error}
+	<ToolError message={error} />
-		<div class="rounded-lg border border-red-200 bg-red-50 p-4 text-sm text-red-800">
-			{error}
-		</div>
-	{/if}
 
 	{#if items.length > 0}
 		<div class="flex justify-end">

src/routes/tools/exhibits/+page.svelte

@@ -0,0 +1,621 @@
+<script lang="ts">
+	import { onDestroy } from 'svelte';
+	import { Files } from '@lucide/svelte';
+	import { PDFDocument, StandardFonts, type RGB } from 'pdf-lib';
+	import ExhibitFileList from '$lib/components/ExhibitFileList.svelte';
+	import FileDropzone from '$lib/components/FileDropzone.svelte';
+	import ToolError from '$lib/components/ToolError.svelte';
+	import Button from '$lib/components/ui/button.svelte';
+	import { createBatchItem, runBatch, type BatchItem } from '$lib/batch';
+	import { downloadBlob } from '$lib/download';
+	import {
+		DEFAULT_EXHIBIT_PREFIX,
+		MAX_EXHIBIT_PREFIX_LENGTH,
+		MAX_EXHIBIT_START_NUMBER,
+		MIN_EXHIBIT_START_NUMBER,
+		buildExhibitFileName,
+		buildExhibitLabel,
+		normalizeExhibitPrefix,
+		normalizeExhibitStartNumber
+	} from '$lib/exhibit-naming';
+	import { pdfProcessingErrorMessage } from '$lib/pdf-errors';
+	import {
+		OVERLAY_POSITION_OPTIONS,
+		getPreviewPositionStyle,
+		parseHexColor,
+		type OverlayPosition
+	} from '$lib/pdf-overlay';
+	import { createPdfSession } from '$lib/pdf-session.svelte';
+	import {
+		MIN_TEXT_OVERLAY_SIZE,
+		TEXT_OVERLAY_MARGIN,
+		drawTextOverlay
+	} from '$lib/pdf-text-overlay';
+	import { getTextFitScale } from '$lib/pdf-preview-text';
+	import {
+		PDF_PREVIEW_SCALE,
+		PreviewRenderCancelledError,
+		loadPdfPageRenderer,
+		type PdfPageImage,
+		type PdfPageRenderer
+	} from '$lib/pdf-thumbnails';
+
+	const PRESETS = ['Anlage', 'Anlage K', 'Anlage B', 'Anlage XYZ'] as const;
+	/** Inner padding of the framed exhibit stamp, in points. */
+	const EXHIBIT_PADDING = 6;
+	const EXHIBIT_TOO_LONG_MESSAGE =
+		'Die Anlagen-Bezeichnung ist für mindestens eine Seite zu lang. Kürzen Sie die Bezeichnung.';
+
+	/** Number and label frozen when a row is created, so results stay valid. */
+	type Assignment = { number: number; label: string };
+
+	type RunOptions = {
+		prefix: string;
+		fontSize: number;
+		color: RGB;
+		position: OverlayPosition;
+		everyPage: boolean;
+		rename: boolean;
+		highestNumber: number;
+	};
+
+	let items = $state<BatchItem[]>([]);
+	let prefix = $state(DEFAULT_EXHIBIT_PREFIX);
+	let startNumberInput = $state<number | undefined>(1);
+	let everyPage = $state(false);
+	let position = $state<OverlayPosition>('top-right');
+	let fontSize = $state(14);
+	let stampColor = $state('#1a1a1a');
+	let rename = $state(true);
+	let assignments = $state(new Map<string, Assignment>());
+	let selectedId = $state<string | null>(null);
+	let isRunning = $state(false);
+	let error = $state<string | null>(null);
+
+	let preview = $state<PdfPageImage | null>(null);
+	let previewError = $state<string | null>(null);
+	let previewRetry = $state(0);
+
+	const session = createPdfSession<PdfPageRenderer>({
+		load: (_file, bytes) => loadPdfPageRenderer(bytes),
+		dispose: (pageRenderer) => pageRenderer.destroy(),
+		onFileChange: () => {
+			preview = null;
+			previewError = null;
+		}
+	});
+
+	const startNumber = $derived(normalizeExhibitStartNumber(startNumberInput));
+	const effectivePrefix = $derived(normalizeExhibitPrefix(prefix));
+	const prefixMissing = $derived(effectivePrefix.length === 0);
+	const pendingCount = $derived(items.filter((item) => item.status === 'pending').length);
+	const canRun = $derived(!isRunning && pendingCount > 0 && !prefixMissing);
+	const hasResults = $derived(items.some((item) => item.status === 'done'));
+
+	const numberFor = (item: BatchItem): number => {
+		const frozen = assignments.get(item.id);
+		if (frozen) return frozen.number;
+
+		const index = items.findIndex((entry) => entry.id === item.id);
+		return startNumber + Math.max(0, index);
+	};
+
+	const labelFor = (item: BatchItem): string =>
+		assignments.get(item.id)?.label ?? buildExhibitLabel(effectivePrefix, numberFor(item));
+
+	const highestNumber = $derived(
+		items.reduce(
+			(highest, item) => Math.max(highest, numberFor(item)),
+			startNumber + Math.max(0, items.length - 1)
+		)
+	);
+
+	/** Freezes number and label once, so reordering never rewrites a result. */
+	/** Freezes number and label once, so reordering never rewrites a result. */
+	const freezeAssignment = (item: BatchItem): Assignment => {
+		const existing = assignments.get(item.id);
+		if (existing) return existing;
+
+		const number = numberFor(item);
+		const assignment = { number, label: buildExhibitLabel(effectivePrefix, number) };
+		assignments = new Map(assignments).set(item.id, assignment);
+		return assignment;
+	};
+
+	const assignmentFor = (item: BatchItem): Assignment =>
+		assignments.get(item.id) ?? freezeAssignment(item);
+
+	const labels = $derived(
+		Object.fromEntries(items.map((item) => [item.id, labelFor(item)])) as Record<string, string>
+	);
+
+	const fileNames = $derived(
+		Object.fromEntries(
+			items.map((item) => [
+				item.id,
+				rename
+					? buildExhibitFileName({
+							prefix: effectivePrefix,
+							number: numberFor(item),
+							highestNumber,
+							originalName: item.file.name
+						})
+					: null
+			])
+		) as Record<string, string | null>
+	);
+
+	const numberExample = $derived(
+		Array.from({ length: Math.min(3, items.length) }, (_, index) => startNumber + index).join(', ')
+	);
+	const prefixExample = $derived(
+		buildExhibitLabel(effectivePrefix || DEFAULT_EXHIBIT_PREFIX, startNumber)
+	);
+	const renameExample = $derived(
+		buildExhibitFileName({
+			prefix: effectivePrefix || DEFAULT_EXHIBIT_PREFIX,
+			number: startNumber,
+			highestNumber,
+			originalName: 'Klageschrift.pdf'
+		})
+	);
+	const selectedLabel = $derived(selectedId ? (labels[selectedId] ?? '') : '');
+	const selectedPageCount = $derived(session.handle?.pageCount ?? 0);
+
+	const previewFit = $derived.by(() => {
+		if (!preview) return { scale: 1, shrunk: false, tooLong: false };
+
+		const pageWidth = preview.width / PDF_PREVIEW_SCALE;
+		const pageHeight = preview.height / PDF_PREVIEW_SCALE;
+		const raw = getTextFitScale(
+			selectedLabel,
+			fontSize,
+			pageWidth - TEXT_OVERLAY_MARGIN * 2 - EXHIBIT_PADDING * 2,
+			pageHeight - TEXT_OVERLAY_MARGIN * 2 - EXHIBIT_PADDING * 2
+		);
+		const minScale = MIN_TEXT_OVERLAY_SIZE / fontSize;
+
+		return { scale: Math.max(raw, minScale), shrunk: raw < 0.999, tooLong: raw < minScale };
+	});
+
+	/** Font size in container-query units so the preview scales like the export. */
+	const previewFontSize = $derived(
+		preview ? ((fontSize * previewFit.scale) / (preview.width / PDF_PREVIEW_SCALE)) * 100 : 0
+	);
+
+	const handleFilesSelected = (files: File[]) => {
+		const knownKeys = new Set(items.map((item) => `${item.file.name}:${item.file.size}`));
+		const additions = files
+			.filter((file) => !knownKeys.has(`${file.name}:${file.size}`))
+			.map((file) => createBatchItem(file));
+		if (additions.length === 0) return;
+
+		items = [...items, ...additions];
+		error = null;
+	};
+
+	const moveItem = (from: number, to: number) => {
+		if (isRunning) return;
+		if (from === to || from < 0 || to < 0 || from >= items.length || to >= items.length) return;
+
+		const next = [...items];
+		const [moved] = next.splice(from, 1);
+		next.splice(to, 0, moved);
+		items = next;
+	};
+
+	const selectItem = (id: string) => {
+		if (isRunning) return;
+
+		if (selectedId === id) {
+			selectedId = null;
+			session.clear();
+			return;
+		}
+
+		const item = items.find((entry) => entry.id === id);
+		if (!item) return;
+
+		selectedId = id;
+		void session.load(item.file);
+	};
+
+	const currentRunOptions = (): RunOptions => ({
+		prefix: effectivePrefix,
+		fontSize: Number(fontSize),
+		color: parseHexColor(stampColor),
+		position,
+		everyPage,
+		rename,
+		highestNumber
+	});
+
+	const processFile = async (file: File, item: BatchItem, options: RunOptions) => {
+		const assignment = assignmentFor(item);
+		const pdfDoc = await PDFDocument.load(new Uint8Array(await file.arrayBuffer()));
+		const font = await pdfDoc.embedFont(StandardFonts.HelveticaBold);
+		const pages = pdfDoc.getPages();
+		const targets = options.everyPage ? pages : pages.slice(0, 1);
+
+		for (const page of targets) {
+			drawTextOverlay(page, {
+				font,
+				text: assignment.label,
+				size: options.fontSize,
+				color: options.color,
+				position: options.position,
+				margin: TEXT_OVERLAY_MARGIN,
+				padding: EXHIBIT_PADDING,
+				framed: true,
+				minSize: MIN_TEXT_OVERLAY_SIZE,
+				compensatePageRotation: true,
+				tooLongMessage: EXHIBIT_TOO_LONG_MESSAGE
+			});
+		}
+
+		const bytes = await pdfDoc.save();
+		const name = options.rename
+			? buildExhibitFileName({
+					prefix: options.prefix,
+					number: assignment.number,
+					highestNumber: options.highestNumber,
+					originalName: file.name
+				})
+			: file.name;
+
+		return { bytes, name };
+	};
+
+	const exhibitErrorMessage = (processingError: unknown) =>
+		pdfProcessingErrorMessage(
+			processingError,
+			'Diese PDF konnte nicht als Anlage erstellt werden. Prüfen Sie die Datei.'
+		);
+
+	const updateItem = (id: string, patch: Partial<BatchItem>) => {
+		items = items.map((item) => (item.id === id ? { ...item, ...patch } : item));
+	};
+
+	const startBatch = async () => {
+		if (isRunning || !canRun) return;
+
+		const queue = items.filter((item) => item.status === 'pending');
+		if (queue.length === 0) return;
+
+		// Freeze every number before the first file is processed: reordering or
+		// changing the start number afterwards must not rewrite a result.
+		for (const item of queue) freezeAssignment(item);
+
+		const options = currentRunOptions();
+		isRunning = true;
+		try {
+			await runBatch(queue, (file, item) => processFile(file, item, options), updateItem, {
+				errorMessage: exhibitErrorMessage,
+				// Skip rows removed while they were still waiting in the queue.
+				shouldProcess: (id) => items.some((item) => item.id === id)
+			});
+		} finally {
+			isRunning = false;
+		}
+	};
+
+	const retryItem = async (id: string) => {
+		if (isRunning) return;
+		const item = items.find((entry) => entry.id === id);
+		if (!item) return;
+
+		const options = currentRunOptions();
+		isRunning = true;
+		try {
+			await runBatch([item], (file, entry) => processFile(file, entry, options), updateItem, {
+				errorMessage: exhibitErrorMessage
+			});
+		} finally {
+			isRunning = false;
+		}
+	};
+
+	const removeItem = (id: string) => {
+		items = items.filter((item) => item.id !== id);
+
+		if (selectedId === id) {
+			selectedId = null;
+			session.clear();
+		}
+	};
+
+	const downloadItem = (item: BatchItem) => {
+		if (item.resultBytes && item.resultName) downloadBlob(item.resultBytes, item.resultName);
+	};
+
+	$effect(() => {
+		const activeRenderer = session.handle;
+		void previewRetry;
+		if (!activeRenderer) return;
+
+		let cancelled = false;
+		void activeRenderer
+			.render(1)
+			.then((result) => {
+				if (cancelled) return;
+				preview = result;
+				previewError = null;
+			})
+			.catch((renderError) => {
+				if (cancelled || renderError instanceof PreviewRenderCancelledError) return;
+				console.error('Failed to render exhibit preview:', renderError);
+				preview = null;
+				previewError = 'Die Vorschau dieser Anlage konnte nicht erzeugt werden.';
+			});
+
+		return () => {
+			cancelled = true;
+		};
+	});
+
+	onDestroy(() => {
+		session.clear();
+	});
+</script>
+
+<svelte:head>
+	<title>Anlagen nummerieren — beA-Edit</title>
+</svelte:head>
+
+<div class="mx-auto flex max-w-5xl flex-col gap-6 pb-10">
+	<div>
+		<div class="mb-2 flex items-center gap-2 text-secondary">
+			<Files class="size-5" aria-hidden="true" />
+			<span class="text-xs font-extrabold tracking-[0.18em] uppercase">Anlagenbezeichnung</span>
+		</div>
+		<h1 class="text-2xl font-bold text-foreground">Anlagen nummerieren</h1>
+		<p class="mt-2 max-w-2xl text-sm text-primary">
+			Versehen Sie mehrere PDFs mit fortlaufenden Anlagen-Bezeichnungen und benennen Sie die Dateien
+			passend um.
+		</p>
+	</div>
+
+	<FileDropzone
+		onFilesSelected={handleFilesSelected}
+		multiple
+		label={items.length === 0 ? 'PDFs als Anlagen hinzufügen' : 'Weitere PDFs hinzufügen'}
+		sublabel={items.length === 0
+			? 'PDFs hier ablegen oder auswählen — eine Datei entspricht einer Anlage'
+			: 'Weitere Anlagen hinzufügen – bestehende Dateien bleiben erhalten'}
+	/>
+
+	{#if items.length > 0}
+		<div class="grid gap-6 {selectedId ? 'lg:grid-cols-[minmax(0,1fr)_minmax(320px,0.9fr)]' : ''}">
+			<section
+				class="flex flex-col gap-5 rounded-2xl border border-border bg-card p-5"
+				aria-labelledby="exhibit-options-title"
+			>
+				<div>
+					<h2 id="exhibit-options-title" class="text-lg font-semibold text-foreground">
+						Anlagen einstellen
+					</h2>
+					<p class="mt-1 text-xs text-muted-foreground">
+						Eine Datei entspricht einer Anlage. Die Einstellungen gelten für alle Dateien der Liste.
+					</p>
+				</div>
+
+				<fieldset class="flex flex-col gap-2">
+					<legend class="text-sm font-medium text-foreground">Bezeichnung</legend>
+					<div class="flex flex-wrap gap-2">
+						{#each PRESETS as preset}
+							<button
+								type="button"
+								class="rounded-full border px-3 py-1.5 text-xs font-bold tracking-wide transition focus:outline-none focus-visible:ring-2 focus-visible:ring-ring {normalizeExhibitPrefix(
+									prefix
+								) === preset
+									? 'border-primary bg-primary text-primary-foreground'
+									: 'border-border bg-background text-foreground hover:border-primary/40'}"
+								aria-pressed={normalizeExhibitPrefix(prefix) === preset}
+								onclick={() => (prefix = preset)}
+							>
+								{preset}
+							</button>
+						{/each}
+					</div>
+				</fieldset>
+
+				<div class="flex flex-col gap-2">
+					<label class="text-sm font-medium text-foreground" for="exhibit-prefix">
+						Bezeichnung (frei wählbar)
+					</label>
+					<input
+						id="exhibit-prefix"
+						type="text"
+						bind:value={prefix}
+						maxlength={MAX_EXHIBIT_PREFIX_LENGTH}
+						class="w-full rounded-lg border border-input bg-background px-3 py-2 text-sm"
+					/>
+					{#if prefixMissing}
+						<p class="text-xs text-destructive" role="status">
+							Bitte geben Sie eine Bezeichnung an, z. B. „Anlage K“.
+						</p>
+					{:else}
+						<p class="text-xs text-muted-foreground" role="status">
+							Beispiel: <span class="font-semibold">{prefixExample}</span>
+						</p>
+					{/if}
+				</div>
+
+				<div class="grid gap-x-4 gap-y-3 sm:grid-cols-[minmax(0,1fr)_auto] sm:items-center">
+					<label class="text-sm font-medium text-foreground" for="exhibit-start-number">
+						Startnummer
+					</label>
+					<input
+						id="exhibit-start-number"
+						type="number"
+						inputmode="numeric"
+						step="1"
+						min={MIN_EXHIBIT_START_NUMBER}
+						max={MAX_EXHIBIT_START_NUMBER}
+						bind:value={startNumberInput}
+						onchange={() => (startNumberInput = startNumber)}
+						onblur={() => (startNumberInput = startNumber)}
+						class="w-full rounded-lg border border-input bg-background px-3 py-2 text-sm sm:w-28"
+					/>
+					{#if items.length > 0}
+						<p class="text-xs text-muted-foreground sm:col-span-2" role="note">
+							{items.length} Datei{items.length === 1 ? '' : 'en'} → {effectivePrefix ||
+								DEFAULT_EXHIBIT_PREFIX}
+							{numberExample}{items.length > 3 ? ', …' : ''}
+						</p>
+					{/if}
+				</div>
+
+				<label class="flex items-center gap-2 text-sm text-foreground" for="exhibit-every-page">
+					<input id="exhibit-every-page" type="checkbox" bind:checked={everyPage} />
+					Auf jeder Seite stempeln
+				</label>
+
+				<div class="grid gap-4 sm:grid-cols-2">
+					<div class="flex flex-col gap-2">
+						<label class="text-sm font-medium text-foreground" for="exhibit-position">
+							Position
+						</label>
+						<select
+							id="exhibit-position"
+							bind:value={position}
+							class="rounded-lg border border-input bg-background px-3 py-2 text-sm"
+						>
+							{#each OVERLAY_POSITION_OPTIONS as option (option.value)}
+								<option value={option.value}>{option.label}</option>
+							{/each}
+						</select>
+					</div>
+					<div class="flex flex-col gap-2">
+						<label class="text-sm font-medium text-foreground" for="exhibit-color">Farbe</label>
+						<input
+							id="exhibit-color"
+							type="color"
+							bind:value={stampColor}
+							class="h-10 w-full cursor-pointer rounded-lg border border-input bg-background p-1"
+						/>
+					</div>
+				</div>
+
+				<div class="grid gap-x-4 gap-y-3 sm:grid-cols-[minmax(0,1fr)_auto] sm:items-center">
+					<label class="text-sm font-medium text-foreground" for="exhibit-font-size">
+						Schriftgröße: {fontSize} pt
+					</label>
+					<input
+						id="exhibit-font-size"
+						type="range"
+						min="10"
+						max="24"
+						bind:value={fontSize}
+						aria-valuetext="{fontSize} Punkt"
+						class="sm:col-span-2"
+					/>
+				</div>
+
+				<div class="flex flex-col gap-2 border-t border-border pt-4">
+					<label class="flex items-center gap-2 text-sm text-foreground" for="exhibit-rename">
+						<input id="exhibit-rename" type="checkbox" bind:checked={rename} />
+						Dateien umbenennen
+					</label>
+					{#if rename}
+						<p class="text-xs text-muted-foreground" role="note">
+							Muster: <code class="rounded bg-muted px-1 py-0.5">{renameExample}</code>
+						</p>
+					{/if}
+				</div>
+
+				{#if isRunning || hasResults}
+					<p class="text-xs text-primary" role="note">
+						Bereits erstellte Anlagen behalten ihre Nummer.
+					</p>
+				{/if}
+			</section>
+
+			{#if selectedId}
+				<section
+					class="flex flex-col gap-4 rounded-2xl border border-border bg-card p-5"
+					aria-labelledby="exhibit-preview-title"
+				>
+					<div class="flex items-start justify-between gap-3">
+						<div>
+							<h2 id="exhibit-preview-title" class="text-lg font-semibold text-foreground">
+								Vorschau
+							</h2>
+							<p class="mt-1 text-xs text-muted-foreground">
+								{selectedLabel} · Seite 1 von {selectedPageCount}
+							</p>
+						</div>
+					</div>
+
+					{#if previewError}
+						<div
+							class="flex flex-col items-center gap-3 rounded-lg border border-border bg-muted/30 p-6 text-center"
+							role="alert"
+						>
+							<p class="text-sm text-foreground">{previewError}</p>
+							<Button variant="tertiary" onclick={() => (previewRetry += 1)}>
+								Erneut versuchen
+							</Button>
+						</div>
+					{:else if preview}
+						<div
+							class="relative mx-auto w-full max-w-lg overflow-hidden rounded-lg border border-border bg-white shadow-sm"
+							style="container-type: inline-size; aspect-ratio: {preview.width} / {preview.height};"
+						>
+							<img src={preview.imageUrl} alt="Vorschau von Seite 1" class="block h-full w-full" />
+							<div class="absolute" style={getPreviewPositionStyle(position)}>
+								<div
+									class="border-2 font-sans leading-tight font-bold whitespace-nowrap"
+									style="border-color: {stampColor}; color: {stampColor}; padding: 0.35em; font-size: {previewFontSize}cqw;"
+									data-testid="exhibit-preview"
+									data-position={position}
+								>
+									{selectedLabel}
+								</div>
+							</div>
+						</div>
+					{:else}
+						<div
+							class="flex aspect-[1/1.414] items-center justify-center rounded-lg border border-border bg-muted/30 text-xs text-muted-foreground"
+						>
+							Vorschau wird geladen …
+						</div>
+					{/if}
+
+					{#if previewFit.tooLong}
+						<p class="text-xs text-destructive" role="status">
+							Die Bezeichnung ist für diese Seite zu lang. Kürzen Sie sie.
+						</p>
+					{:else if previewFit.shrunk}
+						<p class="text-xs text-muted-foreground" role="status">
+							Auf dieser Seite wird die Bezeichnung verkleinert.
+						</p>
+					{/if}
+				</section>
+			{/if}
+		</div>
+
+		<ExhibitFileList
+			{items}
+			{labels}
+			{fileNames}
+			{selectedId}
+			zipBaseName="anlagen"
+			disabled={isRunning}
+			onSelect={selectItem}
+			onMove={moveItem}
+			onDownload={downloadItem}
+			onRemove={removeItem}
+			onRetry={retryItem}
+		/>
+
+		<div class="flex flex-col items-end gap-3">
+			<ToolError message={error} class="w-full" />
+			<Button size="large" onclick={startBatch} disabled={!canRun}>
+				{isRunning ? 'Anlagen werden erstellt …' : 'Anlagen erstellen'}
+			</Button>
+		</div>
+	{:else}
+		<ToolError message={error} />
+	{/if}
+</div>

src/routes/tools/merge/+page.svelte

@@ -1,14 +1,22 @@
 <script lang="ts">
 	import FileDropzone from '$lib/components/FileDropzone.svelte';
+	import ToolError from '$lib/components/ToolError.svelte';
 	import Button from '$lib/components/ui/button.svelte';
-	import { downloadBlob } from '$lib/download';
+	import { goto } from '$app/navigation';
+	import { downloadBlobFile, pdfBytesToBlob } from '$lib/download';
+	import { pdfProcessingErrorMessage } from '$lib/pdf-errors';
+	import { queuePendingFiles } from '$lib/pending-files';
 	import { mergePdfFiles } from '$lib/pdf-processing';
 	import { Trash2 } from '@lucide/svelte';
 
+	type MergeAction = 'download' | 'paginate';
+
 	let pdfFiles: File[] = $state([]);
-	let isProcessing = $state(false);
+	let activeAction = $state<MergeAction | null>(null);
 	let error = $state<string | null>(null);
 
+	const isProcessing = $derived(activeAction !== null);
+
 	const handleFilesSelected = (files: File[]) => {
 		pdfFiles = [...pdfFiles, ...files];
 		error = null;
@@ -26,27 +34,37 @@
 		pdfFiles = newFiles;
 	};
 
-	const mergePdfs = async () => {
+	const runMerge = async (action: MergeAction) => {
-		if (pdfFiles.length < 2) return;
+		if (pdfFiles.length < 2 || activeAction) return;
 
-		isProcessing = true;
+		activeAction = action;
 		error = null;
 
 		try {
-			downloadBlob(await mergePdfFiles(pdfFiles), 'zusammengefuegt.pdf');
+			const merged = pdfBytesToBlob(await mergePdfFiles(pdfFiles));
+
+			if (action === 'paginate') {
+				queuePendingFiles(
+					[new File([merged], 'zusammengefuegt.pdf', { type: 'application/pdf' })],
+					'pagination'
+				);
+				await goto('/tools/pagination');
+			} else {
+				downloadBlobFile(merged, 'zusammengefuegt.pdf');
+			}
 		} catch (err) {
 			console.error('Merge failed:', err);
-			error = 'Fehler beim Zusammenfügen der PDFs.';
+			error = pdfProcessingErrorMessage(err, 'Fehler beim Zusammenfügen der PDFs.');
 		} finally {
-			isProcessing = false;
+			activeAction = null;
 		}
 	};
 </script>
 
 <div class="mx-auto max-w-4xl space-y-6">
 	<div>
-		<h1 class="text-2xl font-bold text-primary-900">PDFs zusammenfügen</h1>
+		<h1 class="text-primary-900 text-2xl font-bold">PDFs zusammenfügen</h1>
-		<p class="mt-2 text-sm text-primary-700">
+		<p class="text-primary-700 mt-2 text-sm">
 			Fügen Sie mehrere PDF-Dateien zu einem einzigen Dokument zusammen.
 		</p>
 	</div>
@@ -55,30 +73,38 @@
 
 	{#if pdfFiles.length > 0}
 		<div class="space-y-4">
-			<div class="flex items-center justify-between">
+			<div class="flex items-center justify-between gap-3">
-				<h2 class="text-lg font-semibold text-primary-900">
+				<h2 class="text-primary-900 text-lg font-semibold">
 					{pdfFiles.length} Datei{pdfFiles.length === 1 ? '' : 'en'} ausgewählt
 				</h2>
-				<Button onclick={mergePdfs} disabled={isProcessing || pdfFiles.length < 2}>
+				<div class="flex flex-wrap items-center justify-end gap-2">
-					{isProcessing ? 'Wird zusammengefügt...' : 'PDFs zusammenfügen'}
+					<Button
-				</Button>
+						variant="tertiary"
+						onclick={() => runMerge('paginate')}
+						disabled={isProcessing || pdfFiles.length < 2}
+					>
+						{activeAction === 'paginate' ? 'Wird zusammengefügt …' : 'Zusammenfügen & paginieren'}
+					</Button>
+					<Button
+						onclick={() => runMerge('download')}
+						disabled={isProcessing || pdfFiles.length < 2}
+					>
+						{activeAction === 'download' ? 'Wird zusammengefügt...' : 'PDFs zusammenfügen'}
+					</Button>
+				</div>
 			</div>
 
-			{#if error}
+			<ToolError message={error} />
-				<div class="rounded-lg border border-red-200 bg-red-50 p-4 text-sm text-red-800">
-					{error}
-				</div>
-			{/if}
 
 			<div class="space-y-2">
 				{#each pdfFiles as file, index}
-					<div class="flex items-center gap-3 rounded-lg border border-primary-200 bg-white p-3">
+					<div class="border-primary-200 flex items-center gap-3 rounded-lg border bg-white p-3">
 						<span
 							class="flex h-8 w-8 items-center justify-center rounded-full bg-primary/10 text-sm font-semibold text-primary"
 						>
 							{index + 1}
 						</span>
-						<span class="flex-1 truncate text-sm text-primary-900">{file.name}</span>
+						<span class="text-primary-900 flex-1 truncate text-sm">{file.name}</span>
 						<div class="flex gap-1">
 							<Button
 								variant="tertiary"

src/routes/tools/metadata/+page.svelte

@@ -1,8 +1,10 @@
 <script lang="ts">
 	import FileDropzone from '$lib/components/FileDropzone.svelte';
+	import ToolError from '$lib/components/ToolError.svelte';
 	import Button from '$lib/components/ui/button.svelte';
 	import { formatBytes } from '$lib/batch';
 	import { downloadBlob } from '$lib/download';
+	import { pdfLoadErrorMessage, pdfProcessingErrorMessage } from '$lib/pdf-errors';
 	import { readPdfMetadata, stripPdfMetadata, type PdfMetadataResult } from '$lib/pdf-metadata';
 	import { AlertTriangle, Info, Lock } from '@lucide/svelte';
 
@@ -25,9 +27,12 @@
 		try {
 			const bytes = new Uint8Array(await selected.arrayBuffer());
 			result = await readPdfMetadata(bytes);
-		} catch {
+		} catch (loadError) {
 			file = null;
-			error = 'Diese Datei konnte nicht als PDF gelesen werden. Bitte prüfen Sie die Datei.';
+			error = pdfLoadErrorMessage(
+				loadError,
+				'Diese Datei konnte nicht als PDF gelesen werden. Bitte prüfen Sie die Datei.'
+			);
 		} finally {
 			isReading = false;
 		}
@@ -41,8 +46,11 @@
 			const bytes = new Uint8Array(await file.arrayBuffer());
 			const cleaned = await stripPdfMetadata(bytes);
 			downloadBlob(cleaned, cleanedFileName);
-		} catch {
+		} catch (cleanError) {
-			error = 'Die Metadaten konnten nicht entfernt werden. Bitte versuchen Sie es erneut.';
+			error = pdfProcessingErrorMessage(
+				cleanError,
+				'Die Metadaten konnten nicht entfernt werden. Bitte versuchen Sie es erneut.'
+			);
 		} finally {
 			isCleaning = false;
 		}
@@ -88,13 +96,11 @@
 	{#if isReading}
 		<p class="text-sm text-primary" role="status">Metadaten werden gelesen …</p>
 	{:else if error}
-		<div class="rounded-lg border border-red-200 bg-red-50 p-4 text-sm text-red-800" role="alert">
+		<ToolError message={error} />
-			{error}
-		</div>
 	{:else if result}
 		{#if result.status === 'encrypted'}
-			<div class="rounded-lg border border-red-200 bg-red-50 p-4 flex gap-3" role="alert">
+			<div class="flex gap-3 rounded-lg border border-red-200 bg-red-50 p-4" role="alert">
-				<Lock class="h-5 w-5 shrink-0 text-red-600 mt-0.5" />
+				<Lock class="mt-0.5 h-5 w-5 shrink-0 text-red-600" />
 				<div class="text-sm text-red-800">
 					<p class="font-medium">Dieses PDF ist verschlüsselt</p>
 					<p class="mt-1">
@@ -105,25 +111,25 @@
 				</div>
 			</div>
 		{:else}
-			<div class="rounded-2xl border border-border bg-card p-6 space-y-5" data-metadata-card>
+			<div class="space-y-5 rounded-2xl border border-border bg-card p-6" data-metadata-card>
 				<div class="flex items-center gap-2 text-foreground">
 					<Info class="h-5 w-5" />
 					<h2 class="text-lg font-semibold">Dokument-Informationen</h2>
 				</div>
-				<p class="text-xs text-primary truncate" title={file?.name}>{file?.name}</p>
+				<p class="truncate text-xs text-primary" title={file?.name}>{file?.name}</p>
 
 				<dl class="grid grid-cols-1 gap-x-6 gap-y-2 sm:grid-cols-[12rem_1fr]">
 					{#each infoRows as row (row.label)}
 						<dt class="text-sm font-medium text-foreground">{row.label}</dt>
-						<dd class="text-sm text-primary wrap-break-word" data-metadata-value={row.label}>
+						<dd class="text-sm wrap-break-word text-primary" data-metadata-value={row.label}>
 							{row.value || '–'}
 						</dd>
 					{/each}
 				</dl>
 
 				{#if result.metadata.embeddedFileSuspected}
-					<div class="rounded-lg border border-amber-200 bg-amber-50 p-4 flex gap-3">
+					<div class="flex gap-3 rounded-lg border border-amber-200 bg-amber-50 p-4">
-						<AlertTriangle class="h-5 w-5 shrink-0 text-amber-600 mt-0.5" />
+						<AlertTriangle class="mt-0.5 h-5 w-5 shrink-0 text-amber-600" />
 						<p class="text-sm text-amber-800">
 							Die Datei enthält möglicherweise eingebettete Anlagen. Diese werden beim Bereinigen
 							nicht entfernt.

src/routes/tools/pagination/+page.svelte

@@ -0,0 +1,354 @@
+<script lang="ts">
+	import { onDestroy, onMount } from 'svelte';
+	import { ListOrdered } from '@lucide/svelte';
+	import FileDropzone from '$lib/components/FileDropzone.svelte';
+	import PaginationPreview from '$lib/components/PaginationPreview.svelte';
+	import RasterizationWarning from '$lib/components/RasterizationWarning.svelte';
+	import ToolError from '$lib/components/ToolError.svelte';
+	import Button from '$lib/components/ui/button.svelte';
+	import { downloadBlob } from '$lib/download';
+	import { pdfProcessingErrorMessage } from '$lib/pdf-errors';
+	import { OVERLAY_POSITION_OPTIONS, type OverlayPosition } from '$lib/pdf-overlay';
+	import {
+		MAX_FONT_SIZE,
+		MAX_FREE_TEXT_LENGTH,
+		MAX_START_NUMBER,
+		MIN_FONT_SIZE,
+		MIN_START_NUMBER,
+		PAGINATION_FORMATS,
+		buildPaginationLabel,
+		normalizeFreeText,
+		normalizeStartNumber,
+		paginatePdf,
+		type PaginationFormat,
+		type PaginationTextScope
+	} from '$lib/pdf-pagination';
+	import { createPdfSession } from '$lib/pdf-session.svelte';
+	import {
+		PreviewRenderCancelledError,
+		loadPdfPageRenderer,
+		type PdfPageImage,
+		type PdfPageRenderer
+	} from '$lib/pdf-thumbnails';
+	import { takePendingFiles } from '$lib/pending-files';
+
+	const session = createPdfSession<PdfPageRenderer>({
+		load: (_file, bytes) => loadPdfPageRenderer(bytes),
+		dispose: (pageRenderer) => pageRenderer.destroy(),
+		onFileChange: () => {
+			currentPage = 1;
+			preview = null;
+			previewError = null;
+		}
+	});
+
+	const file = $derived(session.file);
+	const sourceBytes = $derived(session.bytes);
+	const renderer = $derived(session.handle);
+	const pageCount = $derived(renderer?.pageCount ?? 0);
+
+	let preview = $state<PdfPageImage | null>(null);
+	let previewError = $state<string | null>(null);
+	let previewRetry = $state(0);
+	let currentPage = $state(1);
+	let isProcessing = $state(false);
+	let error = $state<string | null>(null);
+	let startNumberInput = $state<number | undefined>(1);
+	let freeText = $state('');
+	let textScope = $state<PaginationTextScope>('all');
+	let numberFormat = $state<PaginationFormat>('blatt');
+	let position = $state<OverlayPosition>('bottom-center');
+	let fontSize = $state(11);
+
+	const startNumber = $derived(normalizeStartNumber(startNumberInput ?? MIN_START_NUMBER));
+	const labelOptions = $derived({
+		startNumber,
+		freeText: normalizeFreeText(freeText),
+		textScope,
+		format: numberFormat
+	});
+	const previewLabel = $derived(buildPaginationLabel(currentPage - 1, labelOptions));
+	const exampleLabel = $derived(buildPaginationLabel(0, labelOptions));
+	const errorMessage = $derived(error ?? session.loadingError);
+	const canPaginate = $derived(sourceBytes !== null && !isProcessing && !session.isLoading);
+	const freeTextHint = $derived(
+		textScope === 'all'
+			? 'Der Zusatztext erscheint auf jeder Seite.'
+			: 'Der Zusatztext erscheint nur auf der ersten Seite.'
+	);
+	const freeTextCount = $derived(`${normalizeFreeText(freeText).length}/${MAX_FREE_TEXT_LENGTH}`);
+
+	const showPage = (pageNumber: number) => {
+		if (!renderer) return;
+		currentPage = Math.min(Math.max(1, Math.round(pageNumber || 1)), renderer.pageCount);
+	};
+
+	/** Clamps typed input on commit so the field can be cleared while editing. */
+	const commitStartNumber = () => {
+		startNumberInput = startNumber;
+	};
+
+	const handleFilesSelected = (files: File[]) => {
+		const [nextFile] = files;
+		if (nextFile) void session.load(nextFile);
+	};
+
+	const paginate = async () => {
+		const bytes = sourceBytes;
+		const currentFile = file;
+		if (!bytes || !currentFile) return;
+
+		isProcessing = true;
+		error = null;
+
+		try {
+			const output = await paginatePdf(bytes, {
+				startNumber,
+				freeText,
+				textScope,
+				format: numberFormat,
+				position,
+				fontSize
+			});
+			downloadBlob(output, `${currentFile.name.replace(/\.pdf$/i, '')}_paginiert.pdf`);
+		} catch (processingError) {
+			console.error('Pagination failed:', processingError);
+			error = pdfProcessingErrorMessage(
+				processingError,
+				'Das PDF konnte nicht paginiert werden. Prüfen Sie die Datei.'
+			);
+		} finally {
+			isProcessing = false;
+		}
+	};
+
+	$effect(() => {
+		const activeRenderer = renderer;
+		const pageNumber = currentPage;
+		void previewRetry;
+		if (!activeRenderer) return;
+
+		let cancelled = false;
+		void activeRenderer
+			.render(pageNumber)
+			.then((result) => {
+				if (cancelled) return;
+				preview = result;
+				previewError = null;
+			})
+			.catch((renderError) => {
+				if (cancelled || renderError instanceof PreviewRenderCancelledError) return;
+				console.error('Failed to render pagination preview:', renderError);
+				preview = null;
+				previewError = 'Die Vorschau dieser Seite konnte nicht erzeugt werden.';
+			});
+
+		return () => {
+			cancelled = true;
+		};
+	});
+
+	onMount(() => {
+		const [pending] = takePendingFiles('pagination');
+		if (pending) void session.load(pending);
+	});
+
+	onDestroy(() => {
+		session.clear();
+	});
+</script>
+
+<svelte:head>
+	<title>PDF paginieren — beA-Edit</title>
+</svelte:head>
+
+<div class="mx-auto flex max-w-5xl flex-col gap-6 pb-10">
+	<div>
+		<div class="mb-2 flex items-center gap-2 text-secondary">
+			<ListOrdered class="size-5" aria-hidden="true" />
+			<span class="text-xs font-extrabold tracking-[0.18em] uppercase">Seitenzählung</span>
+		</div>
+		<h1 class="text-2xl font-bold text-foreground">Paginieren</h1>
+		<p class="mt-2 max-w-2xl text-sm text-primary">
+			Versehen Sie alle Seiten mit fortlaufenden Blattnummern — auf Wunsch kombiniert mit einem
+			Aktenzeichen.
+		</p>
+	</div>
+
+	<FileDropzone
+		onFilesSelected={handleFilesSelected}
+		label={file ? 'Andere PDF wählen' : 'PDF zum Paginieren hinzufügen'}
+		sublabel={session.isLoading
+			? 'PDF wird geladen …'
+			: file
+				? `${file.name}${pageCount > 0 ? ` · ${pageCount} Seite${pageCount === 1 ? '' : 'n'}` : ''}`
+				: 'PDF hier ablegen oder auswählen'}
+	/>
+
+	{#if file}
+		<RasterizationWarning {file} />
+	{/if}
+
+	{#if file && renderer}
+		<div class="grid gap-6 lg:grid-cols-[minmax(0,1fr)_minmax(320px,0.9fr)]">
+			<section
+				class="flex flex-col gap-5 rounded-2xl border border-border bg-card p-5"
+				aria-labelledby="pagination-options-title"
+			>
+				<div>
+					<h2 id="pagination-options-title" class="text-lg font-semibold text-foreground">
+						Nummerierung einstellen
+					</h2>
+					<p class="mt-1 text-xs text-muted-foreground">
+						Die Nummern laufen über das gesamte Dokument und werden für schmale Seiten automatisch
+						verkleinert (bis {MIN_FONT_SIZE} pt).
+					</p>
+				</div>
+
+				<div class="flex flex-col gap-2">
+					<label class="text-sm font-medium text-foreground" for="pagination-start">
+						Startnummer
+					</label>
+					<input
+						id="pagination-start"
+						type="number"
+						inputmode="numeric"
+						step="1"
+						min={MIN_START_NUMBER}
+						max={MAX_START_NUMBER}
+						bind:value={startNumberInput}
+						onchange={commitStartNumber}
+						onblur={commitStartNumber}
+						class="w-full rounded-lg border border-input bg-background px-3 py-2 text-sm"
+					/>
+					<p class="text-xs text-muted-foreground">
+						Seite 1 erhält diese Nummer, danach zählt das Dokument fortlaufend weiter.
+					</p>
+				</div>
+
+				<div class="flex flex-col gap-2">
+					<label class="text-sm font-medium text-foreground" for="pagination-text">
+						Zusatztext (optional)
+					</label>
+					<input
+						id="pagination-text"
+						type="text"
+						bind:value={freeText}
+						maxlength={MAX_FREE_TEXT_LENGTH}
+						placeholder="z. B. 123 Ja 60/26"
+						aria-describedby="pagination-text-help"
+						class="w-full rounded-lg border border-input bg-background px-3 py-2 text-sm"
+					/>
+					<p id="pagination-text-help" class="text-xs text-muted-foreground">
+						Höchstens {MAX_FREE_TEXT_LENGTH} Zeichen ({freeTextCount}), zum Beispiel ein
+						Aktenzeichen.
+					</p>
+				</div>
+
+				<fieldset class="flex flex-col gap-2">
+					<legend class="text-sm font-medium text-foreground">Zusatztext anzeigen</legend>
+					<label class="flex items-center gap-2 text-sm text-foreground">
+						<input
+							type="radio"
+							name="pagination-text-scope"
+							value="all"
+							checked={textScope === 'all'}
+							onchange={() => (textScope = 'all')}
+						/>
+						Auf jeder Seite
+					</label>
+					<label class="flex items-center gap-2 text-sm text-foreground">
+						<input
+							type="radio"
+							name="pagination-text-scope"
+							value="first"
+							checked={textScope === 'first'}
+							onchange={() => (textScope = 'first')}
+						/>
+						Nur auf der ersten Seite
+					</label>
+					<p class="text-xs text-muted-foreground">{freeTextHint}</p>
+				</fieldset>
+
+				<div class="grid gap-4 sm:grid-cols-2">
+					<div class="flex flex-col gap-2">
+						<label class="text-sm font-medium text-foreground" for="pagination-format">
+							Zahlenformat
+						</label>
+						<select
+							id="pagination-format"
+							bind:value={numberFormat}
+							class="rounded-lg border border-input bg-background px-3 py-2 text-sm"
+						>
+							{#each PAGINATION_FORMATS as format (format.value)}
+								<option value={format.value}>{format.label}</option>
+							{/each}
+						</select>
+					</div>
+					<div class="flex flex-col gap-2">
+						<label class="text-sm font-medium text-foreground" for="pagination-position">
+							Position
+						</label>
+						<select
+							id="pagination-position"
+							bind:value={position}
+							class="rounded-lg border border-input bg-background px-3 py-2 text-sm"
+						>
+							{#each OVERLAY_POSITION_OPTIONS as option (option.value)}
+								<option value={option.value}>{option.label}</option>
+							{/each}
+						</select>
+					</div>
+				</div>
+
+				<div class="grid gap-x-4 gap-y-3 sm:grid-cols-[minmax(0,1fr)_auto] sm:items-center">
+					<label class="text-sm font-medium text-foreground" for="pagination-font-size">
+						Schriftgröße: {fontSize} pt
+					</label>
+					<input
+						id="pagination-font-size"
+						type="range"
+						min={MIN_FONT_SIZE}
+						max={MAX_FONT_SIZE}
+						bind:value={fontSize}
+						aria-valuetext="{fontSize} Punkt"
+						class="sm:col-span-2"
+					/>
+					<p class="text-xs text-muted-foreground sm:col-span-2">
+						Wunschgröße; reicht der Platz nicht, wird der Text bis {MIN_FONT_SIZE} pt verkleinert.
+					</p>
+				</div>
+
+				<p
+					class="rounded-lg border border-border bg-muted/40 px-3 py-2 text-sm text-foreground"
+					data-testid="pagination-example"
+					role="status"
+					aria-live="polite"
+				>
+					Beispiel: {exampleLabel}
+				</p>
+			</section>
+
+			<PaginationPreview
+				{preview}
+				error={previewError}
+				label={previewLabel}
+				{fontSize}
+				{position}
+				{currentPage}
+				{pageCount}
+				onRetry={() => (previewRetry += 1)}
+				onShowPage={showPage}
+			/>
+		</div>
+	{/if}
+
+	<div class="flex flex-col items-end gap-3">
+		<ToolError message={errorMessage} class="w-full" />
+		{#if renderer}
+			<Button size="large" onclick={paginate} disabled={!canPaginate}>
+				{isProcessing ? 'Wird paginiert …' : 'Paginieren & herunterladen'}
+			</Button>
+		{/if}
+	</div>
+</div>

src/routes/tools/rotate/+page.svelte

@@ -2,52 +2,36 @@
 	import { onDestroy } from 'svelte';
 	import { degrees, PDFDocument } from 'pdf-lib';
 	import { RotateCcw, RotateCw } from '@lucide/svelte';
-	import FileDropzone from '$lib/components/FileDropzone.svelte';
 	import PdfPageGrid from '$lib/components/PdfPageGrid.svelte';
+	import SinglePdfTool from '$lib/components/SinglePdfTool.svelte';
 	import Button from '$lib/components/ui/button.svelte';
 	import { downloadBlob } from '$lib/download';
+	import { pdfProcessingErrorMessage } from '$lib/pdf-errors';
+	import { createPdfSession } from '$lib/pdf-session.svelte';
 	import { loadPdfDocument, type PdfDocumentHandle } from '$lib/pdf-thumbnails';
 
-	let pdfFile: File | null = $state(null);
-	let pdfHandle: PdfDocumentHandle | null = $state(null);
 	let rotations = $state(new Map<number, number>());
 	let isProcessing = $state(false);
 	let error = $state<string | null>(null);
-	let loadingError = $state<string | null>(null);
 
+	const session = createPdfSession<PdfDocumentHandle>({
+		load: (_file, bytes) => loadPdfDocument(bytes),
+		dispose: (handle) => handle.destroy(),
+		onFileChange: () => {
+			rotations = new Map();
+			error = null;
+		}
+	});
+
+	const pdfFile = $derived(session.file);
+	const pdfHandle = $derived(session.handle);
+	const pageCount = $derived(pdfHandle?.pageCount ?? 0);
 	const rotatedCount = $derived(rotations.size);
 	const hasRotations = $derived(rotatedCount > 0);
 
-	const isEncryptedPdfError = (loadError: unknown) => {
+	const handleFileSelected = (files: File[]) => {
-		const message =
+		const [file] = files;
-			loadError instanceof Error ? `${loadError.name} ${loadError.message}` : String(loadError);
+		if (file) void session.load(file);
-		return /password|encrypted|encryption|verschl/i.test(message);
-	};
-
-	const loadErrorMessage = (loadError: unknown) =>
-		isEncryptedPdfError(loadError)
-			? 'Dieses PDF ist passwortgeschützt. Entfernen Sie zuerst unter „Passwort entfernen“ den Schutz.'
-			: 'PDF konnte nicht geladen werden. Prüfen Sie, ob die Datei gültig ist.';
-
-	const handleFileSelected = async (files: File[]) => {
-		const file = files[0];
-		if (!file) return;
-
-		pdfHandle?.destroy();
-		pdfHandle = null;
-		pdfFile = file;
-		rotations = new Map();
-		loadingError = null;
-		error = null;
-
-		try {
-			const bytes = new Uint8Array(await file.arrayBuffer());
-			pdfHandle = await loadPdfDocument(bytes);
-		} catch (err) {
-			console.error('Failed to load PDF:', err);
-			loadingError = loadErrorMessage(err);
-			pdfHandle = null;
-		}
 	};
 
 	const rotatePage = (pageNumber: number, delta: number) => {
@@ -63,8 +47,7 @@
 	};
 
 	const rotateAll = (delta: number) => {
-		if (!pdfHandle) return;
+		for (let pageNumber = 1; pageNumber <= pageCount; pageNumber += 1) {
-		for (let pageNumber = 1; pageNumber <= pdfHandle.pageCount; pageNumber += 1) {
 			rotatePage(pageNumber, delta);
 		}
 	};
@@ -88,13 +71,14 @@
 	};
 
 	const rotateAndDownload = async () => {
-		if (!pdfFile || !pdfHandle || !hasRotations) return;
+		const bytes = session.bytes;
+		const currentFile = session.file;
+		if (!bytes || !currentFile || !hasRotations) return;
 
 		isProcessing = true;
 		error = null;
 
 		try {
-			const bytes = new Uint8Array(await pdfFile.arrayBuffer());
 			const pdfDoc = await PDFDocument.load(bytes);
 			for (const [index, page] of pdfDoc.getPages().entries()) {
 				const delta = rotations.get(index + 1);
@@ -104,116 +88,91 @@
 			}
 
 			const resultBytes = await pdfDoc.save();
-			const baseName = pdfFile.name.replace(/\.pdf$/i, '');
+			const baseName = currentFile.name.replace(/\.pdf$/i, '');
 			downloadBlob(resultBytes, `${baseName}_gedreht.pdf`);
 		} catch (err) {
 			console.error('Failed to rotate pages:', err);
-			error = isEncryptedPdfError(err)
+			error = pdfProcessingErrorMessage(err, 'Fehler beim Drehen der Seiten.');
-				? 'Dieses PDF ist passwortgeschützt. Entfernen Sie zuerst unter „Passwort entfernen“ den Schutz.'
-				: 'Fehler beim Drehen der Seiten.';
 		} finally {
 			isProcessing = false;
 		}
 	};
 
 	onDestroy(() => {
-		pdfHandle?.destroy();
+		session.clear();
 	});
 </script>
 
-<div class="mx-auto max-w-4xl space-y-6">
+<SinglePdfTool
-	<div>
+	title="Seiten drehen"
-		<h1 class="text-2xl font-bold text-primary-900">Seiten drehen</h1>
+	description="Drehen Sie einzelne oder alle Seiten eines PDFs — verlustfrei und ohne Qualitätsverlust."
-		<p class="mt-2 text-sm text-primary-700">
+	file={pdfFile}
-			Drehen Sie einzelne oder alle Seiten eines PDFs — verlustfrei und ohne Qualitätsverlust.
+	{pageCount}
-		</p>
+	loadingError={session.loadingError}
-	</div>
+	{error}
+	onFilesSelected={handleFileSelected}
+>
+	{#snippet actions()}
+		<Button variant="tertiary" class="min-w-0 px-3" onclick={() => rotateAll(90)}>
+			Alle 90° rechts
+		</Button>
+		<Button variant="tertiary" class="min-w-0 px-3" onclick={() => rotateAll(270)}>
+			Alle 90° links
+		</Button>
+		<Button variant="tertiary" class="min-w-0 px-3" onclick={() => rotateAll(180)}>
+			Alle 180°
+		</Button>
+		<Button
+			variant="tertiary"
+			class="min-w-0 px-3"
+			onclick={resetRotations}
+			disabled={!hasRotations}
+		>
+			Zurücksetzen
+		</Button>
+	{/snippet}
 
-	{#if !pdfHandle}
+	<PdfPageGrid
-		<FileDropzone onFilesSelected={handleFileSelected} />
+		thumbnails={pdfHandle?.thumbnails ?? []}
-		{#if loadingError}
+		thumbnailWidth={160}
-			<div class="mt-4 rounded-lg border border-red-200 bg-red-50 p-4 text-sm text-red-800">
+		cardClass={previewClass}
-				{loadingError}
+	>
-			</div>
+		{#snippet pageActions(pageNumber)}
-		{/if}
+			{#if (rotations.get(pageNumber) ?? 0) !== 0}
-	{:else}
+				<span
-		<div class="space-y-4">
+					class="absolute top-1 right-1 rounded-full bg-primary px-1.5 py-0.5 text-[10px] font-bold text-white"
-			<FileDropzone
+				>
-				onFilesSelected={handleFileSelected}
+					{rotations.get(pageNumber)}°
-				label="Anderes PDF ablegen"
+				</span>
-				sublabel={pdfFile?.name ?? ''}
-				class="py-4"
-			/>
-			<div class="flex flex-wrap items-center justify-between gap-3">
-				<h2 class="text-lg font-semibold text-primary-900">
-					{pdfFile?.name} — {pdfHandle.pageCount} Seite{pdfHandle.pageCount === 1 ? '' : 'n'}
-				</h2>
-				<div class="flex flex-wrap gap-2">
-					<Button variant="tertiary" class="min-w-0 px-3" onclick={() => rotateAll(90)}>
-						Alle 90° rechts
-					</Button>
-					<Button variant="tertiary" class="min-w-0 px-3" onclick={() => rotateAll(270)}>
-						Alle 90° links
-					</Button>
-					<Button variant="tertiary" class="min-w-0 px-3" onclick={() => rotateAll(180)}>
-						Alle 180°
-					</Button>
-					<Button
-						variant="tertiary"
-						class="min-w-0 px-3"
-						onclick={resetRotations}
-						disabled={!hasRotations}
-					>
-						Zurücksetzen
-					</Button>
-				</div>
-			</div>
-
-			<PdfPageGrid thumbnails={pdfHandle.thumbnails} thumbnailWidth={160} cardClass={previewClass}>
-				{#snippet pageActions(pageNumber)}
-					{#if (rotations.get(pageNumber) ?? 0) !== 0}
-						<span
-							class="absolute top-1 right-1 rounded-full bg-primary px-1.5 py-0.5 text-[10px] font-bold text-white"
-						>
-							{rotations.get(pageNumber)}°
-						</span>
-					{/if}
-					<div class="flex gap-1">
-						<button
-							type="button"
-							class="flex h-7 w-7 items-center justify-center rounded-lg border border-primary-200 bg-white text-primary transition hover:bg-primary-50 focus:outline-none focus-visible:ring-2 focus-visible:ring-primary-400"
-							aria-label="Seite {pageNumber} um 90° nach links drehen"
-							onclick={() => rotatePage(pageNumber, 270)}
-						>
-							<RotateCcw class="h-4 w-4" />
-						</button>
-						<button
-							type="button"
-							class="flex h-7 w-7 items-center justify-center rounded-lg border border-primary-200 bg-white text-primary transition hover:bg-primary-50 focus:outline-none focus-visible:ring-2 focus-visible:ring-primary-400"
-							aria-label="Seite {pageNumber} um 90° nach rechts drehen"
-							onclick={() => rotatePage(pageNumber, 90)}
-						>
-							<RotateCw class="h-4 w-4" />
-						</button>
-					</div>
-				{/snippet}
-			</PdfPageGrid>
-
-			{#if error}
-				<div class="rounded-lg border border-red-200 bg-red-50 p-4 text-sm text-red-800">
-					{error}
-				</div>
 			{/if}
-
+			<div class="flex gap-1">
-			<div class="flex items-center justify-between">
+				<button
-				<p class="text-sm text-primary-700">
+					type="button"
-					{rotatedCount} von {pdfHandle.pageCount} Seite{pdfHandle.pageCount === 1 ? '' : 'n'}
+					class="border-primary-200 hover:bg-primary-50 focus-visible:ring-primary-400 flex h-7 w-7 items-center justify-center rounded-lg border bg-white text-primary transition focus:outline-none focus-visible:ring-2"
-					gedreht
+					aria-label="Seite {pageNumber} um 90° nach links drehen"
-				</p>
+					onclick={() => rotatePage(pageNumber, 270)}
-				<Button onclick={rotateAndDownload} disabled={isProcessing || !hasRotations}>
+				>
-					{isProcessing ? 'Wird verarbeitet...' : 'Drehen & herunterladen'}
+					<RotateCcw class="h-4 w-4" />
-				</Button>
+				</button>
+				<button
+					type="button"
+					class="border-primary-200 hover:bg-primary-50 focus-visible:ring-primary-400 flex h-7 w-7 items-center justify-center rounded-lg border bg-white text-primary transition focus:outline-none focus-visible:ring-2"
+					aria-label="Seite {pageNumber} um 90° nach rechts drehen"
+					onclick={() => rotatePage(pageNumber, 90)}
+				>
+					<RotateCw class="h-4 w-4" />
+				</button>
 			</div>
-		</div>
+		{/snippet}
-	{/if}
+	</PdfPageGrid>
-</div>
+
+	{#snippet footer()}
+		<p class="text-primary-700 text-sm">
+			{rotatedCount} von {pageCount} Seite{pageCount === 1 ? '' : 'n'}
+			gedreht
+		</p>
+		<Button onclick={rotateAndDownload} disabled={isProcessing || !hasRotations}>
+			{isProcessing ? 'Wird verarbeitet...' : 'Drehen & herunterladen'}
+		</Button>
+	{/snippet}
+</SinglePdfTool>

src/routes/tools/separate/+page.svelte

@@ -1,38 +1,34 @@
 <script lang="ts">
 	import { onDestroy } from 'svelte';
-	import FileDropzone from '$lib/components/FileDropzone.svelte';
 	import PdfPageGrid from '$lib/components/PdfPageGrid.svelte';
+	import SinglePdfTool from '$lib/components/SinglePdfTool.svelte';
 	import Button from '$lib/components/ui/button.svelte';
 	import { downloadBlob } from '$lib/download';
+	import { pdfProcessingErrorMessage } from '$lib/pdf-errors';
 	import { copyPagesToNewPdf } from '$lib/pdf-processing';
+	import { createPdfSession } from '$lib/pdf-session.svelte';
 	import { loadPdfDocument, type PdfDocumentHandle } from '$lib/pdf-thumbnails';
 
-	let pdfFile: File | null = $state(null);
-	let pdfHandle: PdfDocumentHandle | null = $state(null);
 	let selectedPages = $state(new Set<number>());
 	let isProcessing = $state(false);
 	let error = $state<string | null>(null);
-	let loadingError = $state<string | null>(null);
 
-	const handleFileSelected = async (files: File[]) => {
+	const session = createPdfSession<PdfDocumentHandle>({
-		const file = files[0];
+		load: (_file, bytes) => loadPdfDocument(bytes),
-		if (!file) return;
+		dispose: (handle) => handle.destroy(),
-
+		onFileChange: () => {
-		pdfHandle?.destroy();
+			selectedPages = new Set();
-		pdfHandle = null;
+			error = null;
-		pdfFile = file;
-		selectedPages = new Set();
-		loadingError = null;
-		error = null;
-
-		try {
-			const bytes = new Uint8Array(await file.arrayBuffer());
-			pdfHandle = await loadPdfDocument(bytes);
-		} catch (err) {
-			console.error('Failed to load PDF:', err);
-			loadingError = 'PDF konnte nicht geladen werden.';
-			pdfHandle = null;
 		}
+	});
+
+	const pdfFile = $derived(session.file);
+	const pdfHandle = $derived(session.handle);
+	const pageCount = $derived(pdfHandle?.pageCount ?? 0);
+
+	const handleFileSelected = (files: File[]) => {
+		const [file] = files;
+		if (file) void session.load(file);
 	};
 
 	const togglePage = (pageNumber: number) => {
@@ -46,9 +42,8 @@
 	};
 
 	const selectAll = () => {
-		if (!pdfHandle) return;
 		const all = new Set<number>();
-		for (let i = 1; i <= pdfHandle.pageCount; i++) all.add(i);
+		for (let pageNumber = 1; pageNumber <= pageCount; pageNumber += 1) all.add(pageNumber);
 		selectedPages = all;
 	};
 
@@ -57,18 +52,18 @@
 	};
 
 	const removePages = async () => {
-		if (!pdfFile || !pdfHandle || selectedPages.size === 0) return;
+		const bytes = session.bytes;
+		const currentFile = session.file;
+		if (!bytes || !currentFile || selectedPages.size === 0) return;
 
 		isProcessing = true;
 		error = null;
 
 		try {
-			const bytes = new Uint8Array(await pdfFile.arrayBuffer());
-
 			const pagesToKeep: number[] = [];
-			for (let i = 0; i < pdfHandle.pageCount; i++) {
+			for (let index = 0; index < pageCount; index += 1) {
-				if (!selectedPages.has(i + 1)) {
+				if (!selectedPages.has(index + 1)) {
-					pagesToKeep.push(i);
+					pagesToKeep.push(index);
 				}
 			}
 
@@ -79,79 +74,46 @@
 			}
 
 			const resultBytes = await copyPagesToNewPdf(bytes, pagesToKeep);
-			const baseName = pdfFile.name.replace(/\.pdf$/i, '');
+			const baseName = currentFile.name.replace(/\.pdf$/i, '');
 			downloadBlob(resultBytes, `${baseName}_ohne_seiten.pdf`);
 		} catch (err) {
 			console.error('Failed to remove pages:', err);
-			error = 'Fehler beim Entfernen der Seiten.';
+			error = pdfProcessingErrorMessage(err, 'Fehler beim Entfernen der Seiten.');
 		} finally {
 			isProcessing = false;
 		}
 	};
 
 	onDestroy(() => {
-		pdfHandle?.destroy();
+		session.clear();
 	});
 </script>
 
-<div class="mx-auto max-w-4xl space-y-6">
+<SinglePdfTool
-	<div>
+	title="Seiten entfernen"
-		<h1 class="text-2xl font-bold text-primary-900">Seiten entfernen</h1>
+	description="Wählen Sie Seiten aus, die Sie aus dem PDF entfernen möchten."
-		<p class="mt-2 text-sm text-primary-700">
+	file={pdfFile}
-			Wählen Sie Seiten aus, die Sie aus dem PDF entfernen möchten.
+	{pageCount}
+	loadingError={session.loadingError}
+	{error}
+	onFilesSelected={handleFileSelected}
+>
+	{#snippet actions()}
+		<Button variant="tertiary" class="min-w-0 px-3" onclick={selectAll}>Alle auswählen</Button>
+		<Button variant="tertiary" class="min-w-0 px-3" onclick={selectNone}>Auswahl aufheben</Button>
+	{/snippet}
+
+	<PdfPageGrid thumbnails={pdfHandle?.thumbnails ?? []} {selectedPages} onPageClick={togglePage} />
+
+	{#snippet footer()}
+		<p class="text-primary-700 text-sm">
+			{selectedPages.size} Seite{selectedPages.size === 1 ? '' : 'n'} zum Entfernen ausgewählt
 		</p>
-	</div>
+		<Button
-
+			onclick={removePages}
-	{#if !pdfHandle}
+			disabled={isProcessing || selectedPages.size === 0 || selectedPages.size >= pageCount}
-		<FileDropzone onFilesSelected={handleFileSelected} />
+		>
-		{#if loadingError}
+			{isProcessing ? 'Wird verarbeitet...' : 'Seiten entfernen & herunterladen'}
-			<div class="mt-4 rounded-lg border border-red-200 bg-red-50 p-4 text-sm text-red-800">
+		</Button>
-				{loadingError}
+	{/snippet}
-			</div>
+</SinglePdfTool>
-		{/if}
-	{:else}
-		<div class="space-y-4">
-			<FileDropzone
-				onFilesSelected={handleFileSelected}
-				label="Anderes PDF ablegen"
-				sublabel={pdfFile?.name ?? ''}
-				class="py-4"
-			/>
-			<div class="flex flex-wrap items-center justify-between gap-3">
-				<h2 class="text-lg font-semibold text-primary-900">
-					{pdfFile?.name} — {pdfHandle.pageCount} Seite{pdfHandle.pageCount === 1 ? '' : 'n'}
-				</h2>
-				<div class="flex gap-2">
-					<Button variant="tertiary" class="min-w-0 px-3" onclick={selectAll}>
-						Alle auswählen
-					</Button>
-					<Button variant="tertiary" class="min-w-0 px-3" onclick={selectNone}>
-						Auswahl aufheben
-					</Button>
-				</div>
-			</div>
-
-			<PdfPageGrid thumbnails={pdfHandle.thumbnails} {selectedPages} onPageClick={togglePage} />
-
-			{#if error}
-				<div class="rounded-lg border border-red-200 bg-red-50 p-4 text-sm text-red-800">
-					{error}
-				</div>
-			{/if}
-
-			<div class="flex items-center justify-between">
-				<p class="text-sm text-primary-700">
-					{selectedPages.size} Seite{selectedPages.size === 1 ? '' : 'n'} zum Entfernen ausgewählt
-				</p>
-				<Button
-					onclick={removePages}
-					disabled={isProcessing ||
-						selectedPages.size === 0 ||
-						selectedPages.size >= pdfHandle.pageCount}
-				>
-					{isProcessing ? 'Wird verarbeitet...' : 'Seiten entfernen & herunterladen'}
-				</Button>
-			</div>
-		</div>
-	{/if}
-</div>

src/routes/tools/stamp/+page.svelte

@@ -1,19 +1,32 @@
 <script lang="ts">
 	import { onDestroy } from 'svelte';
 	import { ChevronLeft, ChevronRight, Stamp } from '@lucide/svelte';
-	import { degrees, PDFDocument, StandardFonts, type PDFFont } from 'pdf-lib';
+	import { PDFDocument, StandardFonts } from 'pdf-lib';
+	import BatchFileList from '$lib/components/BatchFileList.svelte';
 	import FileDropzone from '$lib/components/FileDropzone.svelte';
 	import PdfPageGrid from '$lib/components/PdfPageGrid.svelte';
+	import ToolError from '$lib/components/ToolError.svelte';
 	import Button from '$lib/components/ui/button.svelte';
+	import { createBatchItem, runBatch, type BatchItem } from '$lib/batch';
 	import { downloadBlob } from '$lib/download';
-	import { getPositionCoords, parseHexColor, type OverlayPosition } from '$lib/pdf-overlay';
+	import { pdfLoadErrorMessage, pdfProcessingErrorMessage } from '$lib/pdf-errors';
+	import { createLatestToken } from '$lib/latest-task';
+	import {
+		OVERLAY_POSITION_OPTIONS,
+		getPreviewPositionStyle,
+		parseHexColor,
+		type OverlayPosition
+	} from '$lib/pdf-overlay';
+	import {
+		MIN_TEXT_OVERLAY_SIZE,
+		TEXT_OVERLAY_MARGIN,
+		TEXT_OVERLAY_PADDING,
+		drawImageOverlay,
+		drawTextOverlay
+	} from '$lib/pdf-text-overlay';
 	import { loadPdfDocument, type PdfDocumentHandle } from '$lib/pdf-thumbnails';
 
 	const PRESETS = ['BEGLAUBIGT', 'AUSFERTIGUNG', 'KOPIE', 'EILT', 'ENTWURF', 'ERLEDIGT'] as const;
-	const PADDING = 8;
-	const PAGE_MARGIN = 20;
-	const MIN_EXPORT_FONT_SIZE = 4;
-	const MIN_EXPORT_IMAGE_SIZE = 20;
 
 	type StampImage = {
 		name: string;
@@ -24,7 +37,7 @@
 		height: number;
 	};
 
-	let pdfFile: File | null = $state(null);
+	let items = $state<BatchItem[]>([]);
 	let pdfHandle: PdfDocumentHandle | null = $state(null);
 	let stampInput = $state('BEGLAUBIGT');
 	let withDate = $state(false);
@@ -40,9 +53,9 @@
 	let selectedPages = $state(new Set<number>());
 	let currentPage = $state(1);
 	let isLoading = $state(false);
-	let isProcessing = $state(false);
+	let isRunning = $state(false);
 	let error = $state<string | null>(null);
-	let handleGeneration = 0;
+	const loadToken = createLatestToken();
 
 	const formatGermanDate = (date: Date) =>
 		[date.getDate(), date.getMonth() + 1, date.getFullYear()]
@@ -58,55 +71,55 @@
 	const selectedPreset = $derived(
 		PRESETS.find((preset) => preset === stampInput.trim().toLocaleUpperCase('de-DE'))
 	);
-	const canProcess = $derived(
+	const pendingCount = $derived(items.filter((item) => item.status === 'pending').length);
-		pdfFile !== null &&
+	const stampReady = $derived(stampImage !== null || previewText.length > 0);
-			pdfHandle !== null &&
+	const pageSelectionMissing = $derived(
-			(stampImage !== null || previewText.length > 0) &&
+		items.length === 1 && pdfHandle !== null && !applyToAll && selectedPages.size === 0
-			!isLoading &&
+	);
-			!isLoadingImage &&
+	const canRun = $derived(
-			!isProcessing &&
+		!isRunning && pendingCount > 0 && stampReady && !isLoadingImage && !pageSelectionMissing
-			(applyToAll || selectedPages.size > 0)
 	);
 	const previewFontSize = $derived(
 		Math.max(6, Math.min(Number(fontSize) * 0.5, 240 / Math.max(8, previewText.length * 0.62)))
 	);
 
-	const isEncryptedPdfError = (loadError: unknown) => {
+	const handleFilesSelected = async (files: File[]) => {
-		const message =
+		const knownKeys = new Set(items.map((item) => `${item.file.name}:${item.file.size}`));
-			loadError instanceof Error ? `${loadError.name} ${loadError.message}` : String(loadError);
+		const additions = files
-		return /password|encrypted|encryption|verschl/i.test(message);
+			.filter((file) => !knownKeys.has(`${file.name}:${file.size}`))
-	};
+			.map((file) => createBatchItem(file));
+		if (additions.length === 0) return;
 
-	const loadErrorMessage = (loadError: unknown) =>
+		items = [...items, ...additions];
-		isEncryptedPdfError(loadError)
-			? 'Dieses PDF ist passwortgeschützt. Entfernen Sie zuerst unter „Passwort entfernen“ den Schutz.'
-			: 'PDF konnte nicht geladen werden. Prüfen Sie, ob die Datei gültig ist.';
-
-	const handleFileSelected = async (files: File[]) => {
-		const file = files[0];
-		if (!file) return;
-
-		const generation = ++handleGeneration;
-		pdfHandle?.destroy();
-		pdfHandle = null;
-		pdfFile = file;
 		selectedPages = new Set();
 		currentPage = 1;
 		error = null;
-		isLoading = true;
 
+		// Thumbnails and page selection are only available for a single file so
+		// memory stays flat during multi-file runs.
+		pdfHandle?.destroy();
+		pdfHandle = null;
+		const ticket = loadToken.begin();
+
+		if (items.length !== 1) {
+			isLoading = false;
+			return;
+		}
+
+		const [item] = items;
+		isLoading = true;
 		try {
-			const handle = await loadPdfDocument(new Uint8Array(await file.arrayBuffer()));
+			const handle = await loadPdfDocument(new Uint8Array(await item.file.arrayBuffer()));
-			if (generation !== handleGeneration) {
+			if (!loadToken.isCurrent(ticket) || items.length !== 1) {
 				handle.destroy();
 				return;
 			}
 			pdfHandle = handle;
 		} catch (loadError) {
 			console.error('Failed to load PDF for stamping:', loadError);
-			if (generation === handleGeneration) error = loadErrorMessage(loadError);
+			if (loadToken.isCurrent(ticket)) error = pdfLoadErrorMessage(loadError);
 		} finally {
-			if (generation === handleGeneration) isLoading = false;
+			if (loadToken.isCurrent(ticket)) isLoading = false;
 		}
 	};
 
@@ -189,224 +202,132 @@
 		currentPage = Math.min(pdfHandle.pageCount, currentPage + 1);
 	};
 
-	const getPreviewPositionStyle = (previewPosition: OverlayPosition) => {
+	const processFile = async (file: File) => {
-		switch (previewPosition) {
+		// Options are read per file so a change during a run only affects the
-			case 'center':
+		// still pending files. With multiple files the stamp is applied to all
-				return 'left: 50%; top: 50%; transform: translate(-50%, -50%);';
+		// pages of every file.
-			case 'top-left':
+		const stampText = buildStampText(stampInput, withDate, new Date());
-				return 'left: 5%; top: 5%;';
+		const numericFontSize = Number(fontSize);
-			case 'top-center':
+		const numericImageSize = Number(imageSize);
-				return 'left: 50%; top: 5%; transform: translateX(-50%);';
+		const withFrame = withBorder;
-			case 'top-right':
+		const angle = Number(rotation);
-				return 'right: 5%; top: 5%;';
+		const stampPosition = position;
-			case 'bottom-left':
+		const color = parseHexColor(stampColor);
-				return 'bottom: 5%; left: 5%;';
+		const currentStampImage = stampImage;
-			case 'bottom-center':
+
-				return 'bottom: 5%; left: 50%; transform: translateX(-50%);';
+		const pdfDoc = await PDFDocument.load(new Uint8Array(await file.arrayBuffer()));
-			case 'bottom-right':
+		const font = await pdfDoc.embedFont(StandardFonts.HelveticaBold);
-				return 'bottom: 5%; right: 5%;';
+		const embeddedImage = currentStampImage
+			? currentStampImage.mimeType === 'image/png'
+				? await pdfDoc.embedPng(currentStampImage.bytes)
+				: await pdfDoc.embedJpg(currentStampImage.bytes)
+			: null;
+		const pages = pdfDoc.getPages();
+		const useAllPages = items.length > 1 || applyToAll;
+		const pageIndexes = useAllPages
+			? pages.map((_, index) => index)
+			: Array.from(selectedPages, (pageNumber) => pageNumber - 1);
+
+		for (const pageIndex of pageIndexes) {
+			const page = pages[pageIndex];
+			if (!page) continue;
+
+			if (embeddedImage) {
+				drawImageOverlay(page, {
+					image: embeddedImage,
+					size: numericImageSize,
+					color,
+					position: stampPosition,
+					margin: TEXT_OVERLAY_MARGIN,
+					padding: TEXT_OVERLAY_PADDING,
+					framed: withFrame,
+					rotation: angle
+				});
+				continue;
+			}
+
+			drawTextOverlay(page, {
+				font,
+				text: stampText,
+				size: numericFontSize,
+				color,
+				position: stampPosition,
+				margin: TEXT_OVERLAY_MARGIN,
+				padding: TEXT_OVERLAY_PADDING,
+				framed: true,
+				rotation: angle,
+				minSize: MIN_TEXT_OVERLAY_SIZE,
+				tooLongMessage:
+					'Der Stempeltext ist für mindestens eine Seite zu lang. Kürzen Sie den Text.'
+			});
 		}
+
+		const bytes = await pdfDoc.save();
+		return { bytes, name: `${file.name.replace(/\.pdf$/i, '')}_stempel.pdf` };
 	};
 
-	const getRotatedStampPlacement = (
+	const stampErrorMessage = (processingError: unknown) =>
-		pageWidth: number,
+		pdfProcessingErrorMessage(
-		pageHeight: number,
+			processingError,
-		boxWidth: number,
+			'Diese PDF konnte nicht gestempelt werden. Prüfen Sie die Datei.'
-		boxHeight: number,
-		stampPosition: OverlayPosition,
-		angle: number
-	) => {
-		const radians = (angle * Math.PI) / 180;
-		const cosine = Math.cos(radians);
-		const sine = Math.sin(radians);
-		const rotatedCorners = [
-			{ x: 0, y: 0 },
-			{ x: boxWidth * cosine, y: boxWidth * sine },
-			{ x: -boxHeight * sine, y: boxHeight * cosine },
-			{
-				x: boxWidth * cosine - boxHeight * sine,
-				y: boxWidth * sine + boxHeight * cosine
-			}
-		];
-		const minX = Math.min(...rotatedCorners.map((corner) => corner.x));
-		const maxX = Math.max(...rotatedCorners.map((corner) => corner.x));
-		const minY = Math.min(...rotatedCorners.map((corner) => corner.y));
-		const maxY = Math.max(...rotatedCorners.map((corner) => corner.y));
-		const boundingCoordinates = getPositionCoords(
-			pageWidth,
-			pageHeight,
-			maxX - minX,
-			maxY - minY,
-			stampPosition,
-			PAGE_MARGIN
 		);
 
-		return {
+	const updateItem = (id: string, patch: Partial<BatchItem>) => {
-			x: boundingCoordinates.x - minX,
+		items = items.map((item) => (item.id === id ? { ...item, ...patch } : item));
-			y: boundingCoordinates.y - minY,
-			cosine,
-			sine
-		};
 	};
 
-	const fitStampToPage = (
+	const startBatch = async () => {
-		font: PDFFont,
+		if (isRunning || !canRun) return;
-		text: string,
+		const queue = items.filter((item) => item.status === 'pending');
-		requestedSize: number,
+		if (queue.length === 0) return;
-		pageWidth: number,
-		pageHeight: number
-	) => {
-		const availableWidth = pageWidth - PAGE_MARGIN * 2;
-		const availableHeight = pageHeight - PAGE_MARGIN * 2;
-		let size = requestedSize;
-
-		while (size > MIN_EXPORT_FONT_SIZE) {
-			const width = font.widthOfTextAtSize(text, size) + PADDING * 2;
-			const height = font.heightAtSize(size) + PADDING * 2;
-			if (width <= availableWidth && height <= availableHeight) break;
-			size = Math.max(MIN_EXPORT_FONT_SIZE, size - 0.5);
-		}
-
-		const textWidth = font.widthOfTextAtSize(text, size);
-		const textHeight = font.heightAtSize(size);
-		if (textWidth + PADDING * 2 > availableWidth || textHeight + PADDING * 2 > availableHeight) {
-			throw new Error(
-				'Der Stempeltext ist für mindestens eine Seite zu lang. Kürzen Sie den Text.'
-			);
-		}
-
-		return {
-			size,
-			textHeight,
-			boxWidth: textWidth + PADDING * 2,
-			boxHeight: textHeight + PADDING * 2
-		};
-	};
-
-	const getImageStampBox = (
-		image: { width: number; height: number },
-		pageWidth: number,
-		pageHeight: number
-	) => {
-		const padding = withBorder ? PADDING : 0;
-		const aspectRatio = image.width / image.height;
-		let drawHeight = Number(imageSize);
-		let drawWidth = drawHeight * aspectRatio;
-
-		const availableWidth = pageWidth - PAGE_MARGIN * 2 - padding * 2;
-		const availableHeight = pageHeight - PAGE_MARGIN * 2 - padding * 2;
-		if (drawWidth > availableWidth || drawHeight > availableHeight) {
-			const scale = Math.min(availableWidth / drawWidth, availableHeight / drawHeight);
-			drawWidth *= scale;
-			drawHeight *= scale;
-		}
-		if (drawHeight < MIN_EXPORT_IMAGE_SIZE) {
-			drawHeight = MIN_EXPORT_IMAGE_SIZE;
-			drawWidth = drawHeight * aspectRatio;
-		}
-
-		return {
-			drawWidth,
-			drawHeight,
-			boxWidth: drawWidth + padding * 2,
-			boxHeight: drawHeight + padding * 2,
-			padding
-		};
-	};
-
-	const applyStamp = async () => {
-		if (!pdfFile || !pdfHandle || !canProcess) return;
-
-		isProcessing = true;
-		error = null;
 
+		isRunning = true;
 		try {
-			const stampText = buildStampText(stampInput, withDate, new Date());
+			await runBatch(queue, processFile, updateItem, {
-			const pdfDoc = await PDFDocument.load(new Uint8Array(await pdfFile.arrayBuffer()));
+				errorMessage: stampErrorMessage,
-			const font = await pdfDoc.embedFont(StandardFonts.HelveticaBold);
+				// Skip rows removed while they were still waiting in the queue.
-			const embeddedImage = stampImage
+				shouldProcess: (id) => items.some((item) => item.id === id)
-				? stampImage.mimeType === 'image/png'
+			});
-					? await pdfDoc.embedPng(stampImage.bytes)
-					: await pdfDoc.embedJpg(stampImage.bytes)
-				: null;
-			const pages = pdfDoc.getPages();
-			const pageIndexes = applyToAll
-				? pages.map((_, index) => index)
-				: Array.from(selectedPages, (pageNumber) => pageNumber - 1);
-			const color = parseHexColor(stampColor);
-
-			for (const pageIndex of pageIndexes) {
-				const page = pages[pageIndex];
-				if (!page) continue;
-
-				const { width, height } = page.getSize();
-				const angle = Number(rotation);
-				const box = embeddedImage
-					? getImageStampBox(embeddedImage, width, height)
-					: fitStampToPage(font, stampText, Number(fontSize), width, height);
-				const placement = getRotatedStampPlacement(
-					width,
-					height,
-					box.boxWidth,
-					box.boxHeight,
-					position,
-					angle
-				);
-
-				if (embeddedImage ? withBorder : true) {
-					page.drawRectangle({
-						x: placement.x,
-						y: placement.y,
-						width: box.boxWidth,
-						height: box.boxHeight,
-						borderColor: color,
-						borderWidth: 2,
-						rotate: degrees(angle)
-					});
-				}
-
-				if (embeddedImage) {
-					const imageBox = box as { drawWidth: number; drawHeight: number; padding: number };
-					const offsetX = imageBox.padding;
-					const offsetY = imageBox.padding;
-					page.drawImage(embeddedImage, {
-						x: placement.x + offsetX * placement.cosine - offsetY * placement.sine,
-						y: placement.y + offsetX * placement.sine + offsetY * placement.cosine,
-						width: imageBox.drawWidth,
-						height: imageBox.drawHeight,
-						rotate: degrees(angle)
-					});
-				} else {
-					const textOffsetX = PADDING;
-					const textOffsetY = PADDING + (box as { textHeight: number }).textHeight * 0.2;
-					page.drawText(stampText, {
-						x: placement.x + textOffsetX * placement.cosine - textOffsetY * placement.sine,
-						y: placement.y + textOffsetX * placement.sine + textOffsetY * placement.cosine,
-						size: (box as { size: number }).size,
-						font,
-						color,
-						rotate: degrees(angle)
-					});
-				}
-			}
-
-			const resultBytes = await pdfDoc.save();
-			const baseName = pdfFile.name.replace(/\.pdf$/i, '');
-			downloadBlob(resultBytes, `${baseName}_stempel.pdf`);
-		} catch (processingError) {
-			console.error('Failed to stamp PDF:', processingError);
-			error = isEncryptedPdfError(processingError)
-				? loadErrorMessage(processingError)
-				: processingError instanceof Error && processingError.message.startsWith('Der Stempeltext')
-					? processingError.message
-					: 'Der Stempel konnte nicht angewendet werden. Prüfen Sie die PDF-Datei.';
 		} finally {
-			isProcessing = false;
+			isRunning = false;
 		}
 	};
 
+	const retryItem = async (id: string) => {
+		if (isRunning) return;
+		const item = items.find((entry) => entry.id === id);
+		if (!item) return;
+
+		isRunning = true;
+		try {
+			await runBatch([item], processFile, updateItem, {
+				errorMessage: stampErrorMessage
+			});
+		} finally {
+			isRunning = false;
+		}
+	};
+
+	const removeItem = (id: string) => {
+		const removingPreviewedFile = items.length === 1 && items[0]?.id === id;
+		items = items.filter((item) => item.id !== id);
+		if (removingPreviewedFile) {
+			loadToken.invalidate();
+			pdfHandle?.destroy();
+			pdfHandle = null;
+			selectedPages = new Set();
+			currentPage = 1;
+			error = null;
+			isLoading = false;
+		}
+	};
+
+	const downloadItem = (item: BatchItem) => {
+		if (item.resultBytes && item.resultName) downloadBlob(item.resultBytes, item.resultName);
+	};
+
 	onDestroy(() => {
-		handleGeneration += 1;
+		loadToken.invalidate();
 		pdfHandle?.destroy();
 		if (stampImage) URL.revokeObjectURL(stampImage.objectUrl);
 	});
@@ -429,15 +350,20 @@
 	</div>
 
 	<FileDropzone
-		onFilesSelected={handleFileSelected}
+		onFilesSelected={handleFilesSelected}
-		label={pdfHandle ? 'Anderes PDF ablegen' : 'PDF zum Stempeln hinzufügen'}
+		multiple
+		label={items.length === 0 ? 'PDFs zum Stempeln hinzufügen' : 'Weitere PDFs hinzufügen'}
 		sublabel={isLoading
 			? 'Vorschau wird geladen …'
-			: (pdfFile?.name ?? 'PDF hier ablegen oder auswählen')}
+			: items.length === 1
+				? items[0].file.name
+				: items.length === 0
+					? 'PDFs hier ablegen oder auswählen'
+					: 'Weitere PDFs hinzufügen – bestehende Dateien bleiben erhalten'}
 	/>
 
-	{#if pdfHandle}
+	{#if items.length > 0}
-		<div class="grid gap-6 lg:grid-cols-[minmax(0,1fr)_minmax(320px,0.9fr)]">
+		<div class="grid gap-6 {pdfHandle ? 'lg:grid-cols-[minmax(0,1fr)_minmax(320px,0.9fr)]' : ''}">
 			<section
 				class="flex flex-col gap-5 rounded-2xl border border-border bg-card p-5"
 				aria-labelledby="stamp-options-title"
@@ -447,7 +373,8 @@
 						Stempel einstellen
 					</h2>
 					<p class="mt-1 text-xs text-muted-foreground">
-						Lange Texte werden für kleine Seiten automatisch verkleinert.
+						Lange Texte werden für kleine Seiten automatisch verkleinert. Die Einstellungen gelten
+						für alle Dateien der Liste.
 					</p>
 				</div>
 
@@ -570,13 +497,9 @@
 							bind:value={position}
 							class="rounded-lg border border-input bg-background px-3 py-2 text-sm"
 						>
-							<option value="top-left">Oben links</option>
+							{#each OVERLAY_POSITION_OPTIONS as option (option.value)}
-							<option value="top-center">Oben mittig</option>
+								<option value={option.value}>{option.label}</option>
-							<option value="top-right">Oben rechts</option>
+							{/each}
-							<option value="center">Zentriert</option>
-							<option value="bottom-left">Unten links</option>
-							<option value="bottom-center">Unten mittig</option>
-							<option value="bottom-right">Unten rechts</option>
 						</select>
 					</div>
 					<div class="flex flex-col gap-2">
@@ -590,92 +513,108 @@
 					</div>
 				</div>
 
-				<label class="flex items-center gap-2 text-sm text-foreground" for="stamp-all-pages">
+				{#if items.length > 1}
-					<input id="stamp-all-pages" type="checkbox" bind:checked={applyToAll} />
+					<p class="text-sm text-primary" role="note">
-					Auf alle Seiten anwenden
+						Der Stempel wird auf alle Seiten aller Dateien angewendet.
-				</label>
+					</p>
+				{:else}
+					<label class="flex items-center gap-2 text-sm text-foreground" for="stamp-all-pages">
+						<input id="stamp-all-pages" type="checkbox" bind:checked={applyToAll} />
+						Auf alle Seiten anwenden
+					</label>
+				{/if}
+
+				{#if isRunning}
+					<p class="text-xs text-primary" role="note">
+						Änderungen an den Einstellungen gelten für die noch ausstehenden Dateien.
+					</p>
+				{/if}
 			</section>
 
-			<section
+			{#if pdfHandle}
-				class="flex flex-col gap-4 rounded-2xl border border-border bg-card p-5"
+				<section
-				aria-labelledby="stamp-preview-title"
+					class="flex flex-col gap-4 rounded-2xl border border-border bg-card p-5"
-			>
+					aria-labelledby="stamp-preview-title"
-				<div class="flex items-center justify-between gap-3">
+				>
-					<div>
+					<div class="flex items-center justify-between gap-3">
-						<h2 id="stamp-preview-title" class="text-lg font-semibold text-foreground">Vorschau</h2>
+						<div>
-						<p class="mt-1 text-xs text-muted-foreground">Annäherung an die Ausgabe im PDF</p>
+							<h2 id="stamp-preview-title" class="text-lg font-semibold text-foreground">
-					</div>
+								Vorschau
-					<span class="text-xs font-semibold text-primary"
+							</h2>
-						>{currentPage} / {pdfHandle.pageCount}</span
+							<p class="mt-1 text-xs text-muted-foreground">Annäherung an die Ausgabe im PDF</p>
-					>
-				</div>
-
-				{#if pdfHandle.thumbnails[currentPage - 1]}
-					{@const currentThumbnail = pdfHandle.thumbnails[currentPage - 1]}
-					<div
-						class="relative mx-auto w-full max-w-lg overflow-hidden rounded-lg border border-border bg-white shadow-sm"
-					>
-						<img
-							src={currentThumbnail.imageUrl}
-							alt="Vorschau von Seite {currentPage}"
-							class="block w-full"
-							style="aspect-ratio: {currentThumbnail.width} / {currentThumbnail.height};"
-						/>
-						<div class="absolute max-w-[90%]" style={getPreviewPositionStyle(position)}>
-							{#if stampImage}
-								<div
-									data-testid="stamp-preview"
-									class={withBorder ? 'border-2' : ''}
-									style="border-color: {stampColor}; padding: {withBorder
-										? '2px'
-										: '0'}; transform: rotate({rotation}deg);"
-								>
-									<img
-										src={stampImage.objectUrl}
-										alt="Stempelbild"
-										class="block"
-										style="width: {imageSize * 0.5}px; max-width: 100%;"
-									/>
-								</div>
-							{:else}
-								<div
-									data-testid="stamp-preview"
-									class="border-2 px-2 py-1 font-sans font-extrabold leading-tight whitespace-nowrap"
-									style="border-color: {stampColor}; color: {stampColor}; font-size: {previewFontSize}px; transform: rotate({rotation}deg);"
-								>
-									{previewText}
-								</div>
-							{/if}
 						</div>
+						<span class="text-xs font-semibold text-primary"
+							>{currentPage} / {pdfHandle.pageCount}</span
+						>
 					</div>
-				{/if}
 
-				{#if pdfHandle.pageCount > 1}
+					{#if pdfHandle.thumbnails[currentPage - 1]}
-					<div class="flex items-center justify-center gap-3">
+						{@const currentThumbnail = pdfHandle.thumbnails[currentPage - 1]}
-						<Button
+						<div
-							variant="tertiary"
+							class="relative mx-auto w-full max-w-lg overflow-hidden rounded-lg border border-border bg-white shadow-sm"
-							class="min-w-0 px-3"
-							onclick={showPreviousPage}
-							disabled={currentPage === 1}
-							aria-label="Vorherige Seite"
 						>
-							<ChevronLeft aria-hidden="true" />
+							<img
-						</Button>
+								src={currentThumbnail.imageUrl}
-						<Button
+								alt="Vorschau von Seite {currentPage}"
-							variant="tertiary"
+								class="block w-full"
-							class="min-w-0 px-3"
+								style="aspect-ratio: {currentThumbnail.width} / {currentThumbnail.height};"
-							onclick={showNextPage}
+							/>
-							disabled={currentPage === pdfHandle.pageCount}
+							<div class="absolute max-w-[90%]" style={getPreviewPositionStyle(position)}>
-							aria-label="Nächste Seite"
+								{#if stampImage}
-						>
+									<div
-							<ChevronRight aria-hidden="true" />
+										data-testid="stamp-preview"
-						</Button>
+										class={withBorder ? 'border-2' : ''}
-					</div>
+										style="border-color: {stampColor}; padding: {withBorder
-				{/if}
+											? '2px'
-			</section>
+											: '0'}; transform: rotate({rotation}deg);"
+									>
+										<img
+											src={stampImage.objectUrl}
+											alt="Stempelbild"
+											class="block"
+											style="width: {imageSize * 0.5}px; max-width: 100%;"
+										/>
+									</div>
+								{:else}
+									<div
+										data-testid="stamp-preview"
+										class="border-2 px-2 py-1 font-sans leading-tight font-extrabold whitespace-nowrap"
+										style="border-color: {stampColor}; color: {stampColor}; font-size: {previewFontSize}px; transform: rotate({rotation}deg);"
+									>
+										{previewText}
+									</div>
+								{/if}
+							</div>
+						</div>
+					{/if}
+
+					{#if pdfHandle.pageCount > 1}
+						<div class="flex items-center justify-center gap-3">
+							<Button
+								variant="tertiary"
+								class="min-w-0 px-3"
+								onclick={showPreviousPage}
+								disabled={currentPage === 1}
+								aria-label="Vorherige Seite"
+							>
+								<ChevronLeft aria-hidden="true" />
+							</Button>
+							<Button
+								variant="tertiary"
+								class="min-w-0 px-3"
+								onclick={showNextPage}
+								disabled={currentPage === pdfHandle.pageCount}
+								aria-label="Nächste Seite"
+							>
+								<ChevronRight aria-hidden="true" />
+							</Button>
+						</div>
+					{/if}
+				</section>
+			{/if}
 		</div>
 
-		{#if !applyToAll}
+		{#if pdfHandle && !applyToAll}
 			<section class="flex flex-col gap-3" aria-labelledby="stamp-pages-title">
 				<div>
 					<h2 id="stamp-pages-title" class="text-lg font-semibold text-foreground">
@@ -689,25 +628,21 @@
 			</section>
 		{/if}
 
+		<BatchFileList
+			{items}
+			zipBaseName="stempel"
+			onDownload={downloadItem}
+			onRemove={removeItem}
+			onRetry={retryItem}
+		/>
+
 		<div class="flex flex-col items-end gap-3">
-			{#if error}
+			<ToolError message={error} class="w-full" />
-				<p
+			<Button size="large" onclick={startBatch} disabled={!canRun}>
-					class="w-full rounded-lg border border-destructive/25 bg-card p-4 text-sm text-destructive"
+				{isRunning ? 'Stempel wird angewendet …' : 'Stempel anwenden'}
-					role="alert"
-				>
-					{error}
-				</p>
-			{/if}
-			<Button size="large" onclick={applyStamp} disabled={!canProcess}>
-				{isProcessing ? 'Stempel wird angewendet …' : 'Stempel anwenden & herunterladen'}
 			</Button>
 		</div>
-	{:else if error}
+	{:else}
-		<p
+		<ToolError message={error} />
-			class="rounded-lg border border-destructive/25 bg-card p-4 text-sm text-destructive"
-			role="alert"
-		>
-			{error}
-		</p>
 	{/if}
 </div>

src/routes/tools/watermark/+page.svelte

@@ -4,14 +4,21 @@
 	import BatchFileList from '$lib/components/BatchFileList.svelte';
 	import FileDropzone from '$lib/components/FileDropzone.svelte';
 	import PdfPageGrid from '$lib/components/PdfPageGrid.svelte';
+	import ToolError from '$lib/components/ToolError.svelte';
 	import Button from '$lib/components/ui/button.svelte';
 	import { createBatchItem, runBatch, type BatchItem } from '$lib/batch';
 	import { downloadBlob } from '$lib/download';
+	import { pdfLoadErrorMessage, pdfProcessingErrorMessage } from '$lib/pdf-errors';
 	import { getPositionCoords, parseHexColor, type WatermarkPosition } from '$lib/pdf-overlay';
 	import { loadPdfDocument, type PdfDocumentHandle } from '$lib/pdf-thumbnails';
 
 	type WatermarkKind = 'text' | 'image';
 
+	const WATERMARK_FALLBACK_MESSAGE =
+		'Diese PDF konnte nicht mit einem Wasserzeichen versehen werden.';
+	const watermarkErrorMessage = (error: unknown) =>
+		pdfProcessingErrorMessage(error, WATERMARK_FALLBACK_MESSAGE);
+
 	let items = $state<BatchItem[]>([]);
 	let watermarkKind = $state<WatermarkKind>('text');
 	let watermarkText = $state('VERTRAULICH');
@@ -67,7 +74,7 @@
 			pdfHandle = handle;
 		} catch (loadError) {
 			console.error('Failed to load PDF for watermarking:', loadError);
-			error = 'PDF konnte nicht geladen werden.';
+			error = pdfLoadErrorMessage(loadError);
 		}
 	};
 
@@ -157,7 +164,7 @@
 		isRunning = true;
 		try {
 			await runBatch(queue, processFile, updateItem, {
-				errorMessage: 'Diese PDF konnte nicht mit einem Wasserzeichen versehen werden.',
+				errorMessage: watermarkErrorMessage,
 				// Skip rows removed while they were still waiting in the queue.
 				shouldProcess: (id) => items.some((item) => item.id === id)
 			});
@@ -174,7 +181,7 @@
 		isRunning = true;
 		try {
 			await runBatch([item], processFile, updateItem, {
-				errorMessage: 'Diese PDF konnte nicht mit einem Wasserzeichen versehen werden.'
+				errorMessage: watermarkErrorMessage
 			});
 		} finally {
 			isRunning = false;
@@ -338,11 +345,7 @@
 			/>
 		{/if}
 
-		{#if error}
+		<ToolError message={error} />
-			<div class="rounded-lg border border-red-200 bg-red-50 p-4 text-sm text-red-800">
-				{error}
-			</div>
-		{/if}
 
 		<div class="flex justify-end">
 			<Button onclick={startBatch} disabled={!canRun}>

tests/e2e/exhibits.spec.ts

@@ -0,0 +1,211 @@
+import { expect, test } from '@playwright/test';
+import { unzipSync } from 'fflate';
+import { readFile } from 'node:fs/promises';
+import { PDFDocument } from 'pdf-lib';
+import {
+	createEncryptedPdf,
+	createPdf,
+	dropFiles,
+	expectPdfDownload,
+	getPageContentStreamCount,
+	getPageText,
+	pdfDropzone,
+	trackPageErrors
+} from './helpers';
+
+const row = (page: import('@playwright/test').Page, fileName: string) =>
+	page.locator(`[data-exhibit-item="${fileName}"]`);
+
+const labelOf = (page: import('@playwright/test').Page, fileName: string) =>
+	row(page, fileName).getAttribute('data-exhibit-label');
+
+const renamedOf = (page: import('@playwright/test').Page, fileName: string) =>
+	row(page, fileName).locator('[data-exhibit-filename]').innerText();
+
+test('exhibits numbers dropped PDFs, follows the list order and renames the downloads', async ({
+	page
+}) => {
+	const pageErrors = trackPageErrors(page);
+	const zweiBytes = await createPdf(2, 'Zwei');
+	const zweiInput = await PDFDocument.load(zweiBytes);
+	const originalStreamCounts = zweiInput
+		.getPages()
+		.map((_, pageIndex) => getPageContentStreamCount(zweiInput, pageIndex));
+
+	await page.goto('/tools/exhibits');
+	await dropFiles(page, pdfDropzone(page), [
+		{ name: 'eins.pdf', mimeType: 'application/pdf', buffer: await createPdf(1, 'Eins') },
+		{ name: 'zwei.pdf', mimeType: 'application/pdf', buffer: zweiBytes },
+		{ name: 'drei.pdf', mimeType: 'application/pdf', buffer: await createPdf(3, 'Drei') }
+	]);
+
+	await expect(page.locator('[data-exhibit-item]')).toHaveCount(3);
+	expect(await labelOf(page, 'eins.pdf')).toBe('Anlage 1');
+
+	await page.getByRole('button', { name: 'Anlage K', exact: true }).click();
+	await page.locator('#exhibit-start-number').fill('6');
+	await expect(row(page, 'eins.pdf')).toHaveAttribute('data-exhibit-label', 'Anlage K 6');
+	await expect(row(page, 'drei.pdf')).toHaveAttribute('data-exhibit-label', 'Anlage K 8');
+	expect(await renamedOf(page, 'zwei.pdf')).toBe('→ Anlage_K_07_zwei.pdf');
+
+	// Reordering the second file to the front renumbers the pending rows.
+	await page.getByRole('button', { name: 'zwei.pdf nach oben verschieben' }).click();
+	await expect(row(page, 'zwei.pdf')).toHaveAttribute('data-exhibit-label', 'Anlage K 6');
+	await expect(row(page, 'eins.pdf')).toHaveAttribute('data-exhibit-label', 'Anlage K 7');
+	expect(await renamedOf(page, 'zwei.pdf')).toBe('→ Anlage_K_06_zwei.pdf');
+
+	// The preview renders only the selected Anlage, page 1, on demand.
+	await page.getByRole('button', { name: 'Vorschau für zwei.pdf' }).click();
+	await expect(page.getByTestId('exhibit-preview')).toContainText('Anlage K 6');
+	await expect(page.getByTestId('exhibit-preview')).toHaveAttribute('data-position', 'top-right');
+	await expect(page.getByText('Seite 1 von 2')).toBeVisible();
+
+	await page.getByRole('button', { name: 'Anlagen erstellen', exact: true }).click();
+	await expect(page.getByText('Fertig ✓')).toHaveCount(3, { timeout: 30_000 });
+
+	const downloadPromise = page.waitForEvent('download');
+	await page.getByRole('button', { name: 'zwei.pdf herunterladen' }).click();
+	const outputBytes = await expectPdfDownload(await downloadPromise, /^Anlage_K_06_zwei\.pdf$/);
+
+	const output = await PDFDocument.load(outputBytes);
+	expect(output.getPageCount()).toBe(2);
+	expect(getPageText(output, 0)).toContain('Anlage K 6');
+	// Only the first page is stamped by default; page 2 keeps its stream count.
+	expect(getPageContentStreamCount(output, 1)).toBe(originalStreamCounts[1]);
+	expect(getPageText(output, 1)).not.toContain('Anlage K 6');
+	expect(pageErrors).toEqual([]);
+});
+
+test('exhibits switches to three digits from 98 and keeps labels unpadded', async ({ page }) => {
+	const pageErrors = trackPageErrors(page);
+	await page.goto('/tools/exhibits');
+	await dropFiles(page, pdfDropzone(page), [
+		{ name: 'a.pdf', mimeType: 'application/pdf', buffer: await createPdf(1, 'A') },
+		{ name: 'b.pdf', mimeType: 'application/pdf', buffer: await createPdf(1, 'B') },
+		{ name: 'c.pdf', mimeType: 'application/pdf', buffer: await createPdf(1, 'C') }
+	]);
+
+	await page.locator('#exhibit-start-number').fill('98');
+	await expect(row(page, 'a.pdf')).toHaveAttribute('data-exhibit-label', 'Anlage 98');
+	expect(await renamedOf(page, 'a.pdf')).toBe('→ Anlage_098_a.pdf');
+	expect(await renamedOf(page, 'c.pdf')).toBe('→ Anlage_100_c.pdf');
+
+	await page.getByRole('button', { name: 'Anlagen erstellen', exact: true }).click();
+	await expect(page.getByText('Fertig ✓')).toHaveCount(3, { timeout: 30_000 });
+
+	const downloadPromise = page.waitForEvent('download');
+	await page.getByRole('button', { name: 'a.pdf herunterladen' }).click();
+	const first = await expectPdfDownload(await downloadPromise, /^Anlage_098_a\.pdf$/);
+	expect(getPageText(await PDFDocument.load(first), 0)).toContain('Anlage 98');
+
+	const secondPromise = page.waitForEvent('download');
+	await page.getByRole('button', { name: 'c.pdf herunterladen' }).click();
+	await expectPdfDownload(await secondPromise, /^Anlage_100_c\.pdf$/);
+	expect(pageErrors).toEqual([]);
+});
+
+test('exhibits keeps the original names and honours the every-page option', async ({ page }) => {
+	const pageErrors = trackPageErrors(page);
+	await page.goto('/tools/exhibits');
+	await dropFiles(page, pdfDropzone(page), [
+		{ name: 'original.pdf', mimeType: 'application/pdf', buffer: await createPdf(2, 'Original') }
+	]);
+
+	await page.getByRole('checkbox', { name: 'Dateien umbenennen' }).uncheck();
+	await expect(row(page, 'original.pdf').locator('[data-exhibit-filename]')).toHaveCount(0);
+
+	await page.getByRole('checkbox', { name: 'Auf jeder Seite stempeln' }).check();
+	await page.getByRole('button', { name: 'Anlagen erstellen', exact: true }).click();
+	await expect(page.getByText('Fertig ✓')).toBeVisible({ timeout: 20_000 });
+
+	const downloadPromise = page.waitForEvent('download');
+	await page.getByRole('button', { name: 'original.pdf herunterladen' }).click();
+	const outputBytes = await expectPdfDownload(await downloadPromise, /^original\.pdf$/);
+	const output = await PDFDocument.load(outputBytes);
+	expect(getPageText(output, 0)).toContain('Anlage 1');
+	expect(getPageText(output, 1)).toContain('Anlage 1');
+	expect(pageErrors).toEqual([]);
+});
+
+test('exhibits freezes the number of finished rows and says so', async ({ page }) => {
+	const pageErrors = trackPageErrors(page);
+	await page.goto('/tools/exhibits');
+	await dropFiles(page, pdfDropzone(page), [
+		{ name: 'erst.pdf', mimeType: 'application/pdf', buffer: await createPdf(1, 'Erst') },
+		{ name: 'dann.pdf', mimeType: 'application/pdf', buffer: await createPdf(1, 'Dann') }
+	]);
+
+	await page.getByRole('button', { name: 'Anlagen erstellen', exact: true }).click();
+	await expect(page.getByText('Fertig ✓')).toHaveCount(2, { timeout: 20_000 });
+	await expect(row(page, 'erst.pdf')).toHaveAttribute('data-exhibit-label', 'Anlage 1');
+
+	await page.getByRole('button', { name: 'dann.pdf nach oben verschieben' }).click();
+
+	await expect(row(page, 'dann.pdf')).toHaveAttribute('data-exhibit-label', 'Anlage 2');
+	await expect(row(page, 'erst.pdf')).toHaveAttribute('data-exhibit-label', 'Anlage 1');
+	expect(await renamedOf(page, 'dann.pdf')).toBe('→ Anlage_02_dann.pdf');
+	expect(pageErrors).toEqual([]);
+});
+
+test('exhibits blocks an empty designation and recovers from a broken file', async ({ page }) => {
+	const pageErrors = trackPageErrors(page);
+	await page.goto('/tools/exhibits');
+	await dropFiles(page, pdfDropzone(page), [
+		{ name: 'gut.pdf', mimeType: 'application/pdf', buffer: await createPdf(1, 'Gut') },
+		{ name: 'kaputt.pdf', mimeType: 'application/pdf', buffer: Buffer.from('kein PDF') }
+	]);
+
+	await page.locator('#exhibit-prefix').fill('   ');
+	await expect(page.getByText('Bitte geben Sie eine Bezeichnung an')).toBeVisible();
+	await expect(page.getByRole('button', { name: 'Anlagen erstellen', exact: true })).toBeDisabled();
+
+	await page.locator('#exhibit-prefix').fill('Anlage B');
+	await page.getByRole('button', { name: 'Anlagen erstellen', exact: true }).click();
+	await expect(page.getByText('Fertig ✓')).toHaveCount(1, { timeout: 20_000 });
+	await expect(row(page, 'kaputt.pdf')).toContainText('Fehler');
+	await expect(row(page, 'gut.pdf')).toHaveAttribute('data-exhibit-label', 'Anlage B 1');
+	expect(pageErrors).toEqual([]);
+});
+
+test('exhibits bundles all finished Anlagen in one ZIP', async ({ page }) => {
+	const pageErrors = trackPageErrors(page);
+	await page.goto('/tools/exhibits');
+	await dropFiles(page, pdfDropzone(page), [
+		{ name: 'eins.pdf', mimeType: 'application/pdf', buffer: await createPdf(1, 'Eins') },
+		{ name: 'zwei.pdf', mimeType: 'application/pdf', buffer: await createPdf(1, 'Zwei') }
+	]);
+
+	await page.getByRole('button', { name: 'Anlagen erstellen', exact: true }).click();
+	await expect(page.getByText('Fertig ✓')).toHaveCount(2, { timeout: 20_000 });
+
+	const downloadPromise = page.waitForEvent('download');
+	await page.getByRole('button', { name: 'Alle herunterladen' }).click();
+	const download = await downloadPromise;
+	expect(download.suggestedFilename()).toMatch(/^anlagen_\d{4}-\d{2}-\d{2}\.zip$/);
+
+	const zipPath = await download.path();
+	expect(zipPath).not.toBeNull();
+	expect(Object.keys(unzipSync(new Uint8Array(await readFile(zipPath!)))).sort()).toEqual([
+		'Anlage_01_eins.pdf',
+		'Anlage_02_zwei.pdf'
+	]);
+	expect(pageErrors).toEqual([]);
+});
+
+test('exhibits reports encrypted PDFs as row errors and keeps going', async ({ page }) => {
+	const pageErrors = trackPageErrors(page);
+	await page.goto('/tools/exhibits');
+	await dropFiles(page, pdfDropzone(page), [
+		{
+			name: 'gesperrt.pdf',
+			mimeType: 'application/pdf',
+			buffer: await createEncryptedPdf(1, 'Gesperrt', 'geheim')
+		},
+		{ name: 'offen.pdf', mimeType: 'application/pdf', buffer: await createPdf(1, 'Offen') }
+	]);
+
+	await page.getByRole('button', { name: 'Anlagen erstellen', exact: true }).click();
+	await expect(page.getByText('Fertig ✓')).toHaveCount(1, { timeout: 20_000 });
+	await expect(row(page, 'gesperrt.pdf')).toContainText('passwortgeschützt');
+	expect(pageErrors).toEqual([]);
+});

tests/e2e/helpers.ts

@@ -123,6 +123,127 @@ export const getPageContentText = (document: PDFDocument, pageIndex: number) =>
 		.join('\n');
 };
 
+const PDF_STRING_ESCAPES: Record<string, string> = {
+	n: '\n',
+	r: '\r',
+	t: '\t',
+	b: '\b',
+	f: '\f',
+	'(': '(',
+	')': ')',
+	'\\': '\\'
+};
+
+/** Decodes a single PDF string token (`<hex>` or `(literal)`). */
+const decodePdfString = (token: string): string => {
+	if (token.startsWith('<')) {
+		return Buffer.from(token.slice(1, -1).replace(/\s/g, ''), 'hex').toString('latin1');
+	}
+
+	const raw = token.slice(1, -1);
+	let decoded = '';
+
+	for (let index = 0; index < raw.length; index += 1) {
+		const char = raw[index];
+
+		if (char !== '\\') {
+			decoded += char;
+			continue;
+		}
+
+		const escaped = raw[index + 1];
+		index += 1;
+
+		if (escaped === undefined) break;
+
+		if (escaped >= '0' && escaped <= '7') {
+			let octal = escaped;
+
+			while (octal.length < 3 && raw[index + 1] >= '0' && raw[index + 1] <= '7') {
+				octal += raw[(index += 1)];
+			}
+
+			decoded += String.fromCharCode(Number.parseInt(octal, 8));
+			continue;
+		}
+
+		decoded += PDF_STRING_ESCAPES[escaped] ?? escaped;
+	}
+
+	return decoded;
+};
+
+const PDF_STRING_TOKEN = String.raw`<[0-9a-fA-F\s]*>|\((?:\\.|[^()\\])*\)`;
+const TEXT_SHOWING_PATTERN = new RegExp(
+	String.raw`\[((?:[^\[\]\\]|\\.)*)\]\s*TJ|(${PDF_STRING_TOKEN})\s*(?:Tj|'|")`,
+	'g'
+);
+const STRING_TOKEN_PATTERN = new RegExp(PDF_STRING_TOKEN, 'g');
+
+/**
+ * Decoded operands of every text-showing operator (`Tj`, `TJ`, `'`, `"`).
+ * pdf-lib writes drawn text as hex strings (`<426C2E2031> Tj`), so the raw
+ * content stream is not readable without this decoding.
+ *
+ * Limitations: other text operators (`Td`, `Tf`, …) and non-text strings are
+ * ignored. A page that shows text through an operator this helper does not know
+ * returns `[]`, so `not.toContain(...)` assertions on it prove nothing — assert
+ * on a positive match instead.
+ */
+export const getPageTextValues = (document: PDFDocument, pageIndex: number) => {
+	const content = getPageContentText(document, pageIndex);
+	const values: string[] = [];
+
+	for (const match of content.matchAll(TEXT_SHOWING_PATTERN)) {
+		const [, arrayBody, singleToken] = match;
+
+		if (singleToken !== undefined) {
+			values.push(decodePdfString(singleToken));
+			continue;
+		}
+
+		for (const token of arrayBody.matchAll(STRING_TOKEN_PATTERN)) {
+			values.push(decodePdfString(token[0]));
+		}
+	}
+
+	return values;
+};
+
+export const getPageText = (document: PDFDocument, pageIndex: number) =>
+	getPageTextValues(document, pageIndex).join('\n');
+
+export type PageTextMatrix = { a: number; b: number; c: number; d: number; x: number; y: number };
+
+/**
+ * Translation and rotation of every text matrix (`Tm`) in a page's content
+ * stream, in drawing order. Lets tests assert on the drawing geometry without
+ * hard-coding the hex-encoded text operands.
+ */
+export const getPageTextMatrices = (document: PDFDocument, pageIndex: number): PageTextMatrix[] => {
+	const content = getPageContentText(document, pageIndex);
+	const matrices: PageTextMatrix[] = [];
+
+	for (const match of content.matchAll(
+		/([-\d.]+) ([-\d.]+) ([-\d.]+) ([-\d.]+) ([-\d.]+) ([-\d.]+) Tm/g
+	)) {
+		const [a, b, c, d, x, y] = match.slice(1).map(Number);
+		matrices.push({ a, b, c, d, x, y });
+	}
+
+	if (matrices.length === 0) throw new Error(`Page ${pageIndex + 1} contains no text matrix.`);
+
+	return matrices;
+};
+
+/** First text matrix of a page (the only one in a single-mark document). */
+export const getPageTextMatrix = (document: PDFDocument, pageIndex: number): PageTextMatrix =>
+	getPageTextMatrices(document, pageIndex)[0];
+
+/** Angle of a text matrix in degrees, normalised to `0 … 359`. */
+export const getPageTextAngle = (matrix: PageTextMatrix) =>
+	((Math.atan2(matrix.b, matrix.a) * 180) / Math.PI + 360) % 360;
+
 export const createEncryptedPdf = async (pageCount: number, label: string, password: string) => {
 	const document = await EncryptablePdfDocument.load(await createPdf(pageCount, label));
 	document.encrypt({

tests/e2e/pagination.spec.ts

@@ -0,0 +1,197 @@
+import { expect, test, type Page } from '@playwright/test';
+import { PDFDocument } from 'pdf-lib';
+import { PAGE_NUMBER_MARGIN } from '../../src/lib/pdf-pagination';
+import {
+	createEncryptedPdf,
+	createPdf,
+	createPreRotatedPdf,
+	dropFiles,
+	expectPdfDownload,
+	getPageContentText,
+	getPageText,
+	getPageTextAngle,
+	getPageTextMatrices,
+	getPageTextValues,
+	pdfDropzone,
+	trackPageErrors
+} from './helpers';
+
+/**
+ * Number of text operands equal to `label` on a page. The source documents carry
+ * their own text, so this counts the stamped sheet label instead of comparing
+ * the whole page.
+ */
+const countLabel = (document: PDFDocument, pageIndex: number, label: string) =>
+	getPageTextValues(document, pageIndex).filter((value) => value === label).length;
+
+const downloadPaginated = async (page: Page, fileName: RegExp) => {
+	const downloadPromise = page.waitForEvent('download');
+	await page.getByRole('button', { name: 'Paginieren & herunterladen' }).click();
+	return expectPdfDownload(await downloadPromise, fileName);
+};
+
+test('pagination stamps every page with an Aktenzeichen and the configured start number', async ({
+	page
+}) => {
+	const pageErrors = trackPageErrors(page);
+	await page.goto('/tools/pagination');
+	await dropFiles(page, pdfDropzone(page), [
+		{ name: 'akte.pdf', mimeType: 'application/pdf', buffer: await createPdf(3, 'Akte') }
+	]);
+
+	await expect(page.getByText('Seite 1 von 3')).toBeVisible();
+	await page.locator('#pagination-start').fill('26');
+	await page.locator('#pagination-text').fill('123 Ja 60/26');
+	await expect(page.getByTestId('pagination-example')).toContainText(
+		'Beispiel: 123 Ja 60/26, Bl. 26'
+	);
+
+	await page.getByRole('button', { name: 'Nächste Seite' }).click();
+	await expect(page.getByText('Seite 2 von 3')).toBeVisible();
+	await expect(page.getByTestId('pagination-preview')).toContainText('123 Ja 60/26, Bl. 27');
+
+	const bytes = await downloadPaginated(page, /^akte_paginiert\.pdf$/);
+	const output = await PDFDocument.load(bytes);
+	expect(output.getPageCount()).toBe(3);
+	// Exactly one label per page: a duplicated draw would still pass `toContain`.
+	expect(countLabel(output, 0, '123 Ja 60/26, Bl. 26')).toBe(1);
+	expect(countLabel(output, 1, '123 Ja 60/26, Bl. 27')).toBe(1);
+	expect(countLabel(output, 2, '123 Ja 60/26, Bl. 28')).toBe(1);
+	expect(pageErrors).toEqual([]);
+});
+
+test('pagination can keep the additional text on the first page only', async ({ page }) => {
+	const pageErrors = trackPageErrors(page);
+	await page.goto('/tools/pagination');
+	await dropFiles(page, pdfDropzone(page), [
+		{ name: 'akte.pdf', mimeType: 'application/pdf', buffer: await createPdf(3, 'Akte') }
+	]);
+
+	await page.locator('#pagination-start').fill('7');
+	await page.locator('#pagination-text').fill('AZ 7/26');
+	await page.locator('#pagination-format').selectOption('s');
+	await page.getByLabel('Nur auf der ersten Seite').check();
+	await expect(page.getByTestId('pagination-example')).toContainText('AZ 7/26, S. 7');
+
+	await page.getByRole('button', { name: 'Nächste Seite' }).click();
+	await expect(page.getByTestId('pagination-preview')).toHaveText('S. 8');
+
+	const bytes = await downloadPaginated(page, /^akte_paginiert\.pdf$/);
+	const output = await PDFDocument.load(bytes);
+	expect(output.getPageCount()).toBe(3);
+	expect(getPageText(output, 0)).toContain('AZ 7/26, S. 7');
+	expect(getPageText(output, 1)).toContain('S. 8');
+	expect(getPageText(output, 1)).not.toContain('AZ 7/26');
+	expect(getPageText(output, 2)).toContain('S. 9');
+	expect(pageErrors).toEqual([]);
+});
+
+test('pagination supports number-only labels and jumps to a page', async ({ page }) => {
+	const pageErrors = trackPageErrors(page);
+	await page.goto('/tools/pagination');
+	await dropFiles(page, pdfDropzone(page), [
+		{ name: 'nummern.pdf', mimeType: 'application/pdf', buffer: await createPdf(11, 'Nummern') }
+	]);
+
+	await page.locator('#pagination-start').fill('42');
+	await page.locator('#pagination-format').selectOption('nummer');
+	await expect(page.getByTestId('pagination-example')).toHaveText('Beispiel: 42');
+
+	await page.getByLabel('Springe zu Seite').fill('11');
+	await expect(page.getByText('Seite 11 von 11')).toBeVisible();
+	await expect(page.getByTestId('pagination-preview')).toHaveText('52');
+
+	const bytes = await downloadPaginated(page, /^nummern_paginiert\.pdf$/);
+	const output = await PDFDocument.load(bytes);
+	expect(output.getPageCount()).toBe(11);
+	expect(getPageText(output, 0)).toContain('42');
+	expect(getPageText(output, 10)).toContain('52');
+	expect(pageErrors).toEqual([]);
+});
+
+test('pagination keeps the page number upright on rotated scans', async ({ page }) => {
+	const pageErrors = trackPageErrors(page);
+	await page.goto('/tools/pagination');
+	await dropFiles(page, pdfDropzone(page), [
+		{
+			name: 'gedreht.pdf',
+			mimeType: 'application/pdf',
+			buffer: await createPreRotatedPdf(2, 'Gedreht')
+		}
+	]);
+
+	const bytes = await downloadPaginated(page, /^gedreht_paginiert\.pdf$/);
+	const output = await PDFDocument.load(bytes);
+	expect(output.getPageCount()).toBe(2);
+
+	// `createPreRotatedPdf` stores 420×594 pages and puts /Rotate 90 on page 1, so
+	// the page is displayed as 594×420. The label is counter-rotated so it reads
+	// horizontally on screen instead of sideways.
+	// The stamp is the last text drawn on the page.
+	const rotated = getPageTextMatrices(output, 0).at(-1)!;
+	expect(Math.round(getPageTextAngle(rotated))).toBe(90);
+	expect(countLabel(output, 0, 'Bl. 1')).toBe(1);
+	// Visual bottom centre maps back into user space as x = stored width − margin.
+	expect(rotated.x).toBeCloseTo(420 - PAGE_NUMBER_MARGIN, -1);
+	// …and stays horizontally centred on the displayed width.
+	expect(Math.abs(rotated.y - 594 / 2)).toBeLessThan(15);
+
+	const plain = getPageTextMatrices(output, 1).at(-1)!;
+	expect(Math.round(getPageTextAngle(plain))).toBe(0);
+	expect(countLabel(output, 1, 'Bl. 2')).toBe(1);
+	expect(pageErrors).toEqual([]);
+});
+
+test('pagination offers the "Seite" format and applies it to every page', async ({ page }) => {
+	const pageErrors = trackPageErrors(page);
+	await page.goto('/tools/pagination');
+	await dropFiles(page, pdfDropzone(page), [
+		{ name: 'formate.pdf', mimeType: 'application/pdf', buffer: await createPdf(2, 'Formate') }
+	]);
+
+	await page.locator('#pagination-format').selectOption('seite');
+	await expect(page.getByTestId('pagination-example')).toHaveText('Beispiel: Seite 1');
+
+	const bytes = await downloadPaginated(page, /^formate_paginiert\.pdf$/);
+	const output = await PDFDocument.load(bytes);
+	expect(countLabel(output, 0, 'Seite 1')).toBe(1);
+	expect(countLabel(output, 1, 'Seite 2')).toBe(1);
+	expect(pageErrors).toEqual([]);
+});
+
+test('pagination explains how to handle a password-protected PDF', async ({ page }) => {
+	const pageErrors = trackPageErrors(page);
+	await page.goto('/tools/pagination');
+	await dropFiles(page, pdfDropzone(page), [
+		{
+			name: 'geschuetzt.pdf',
+			mimeType: 'application/pdf',
+			buffer: await createEncryptedPdf(1, 'Geschützt', 'test-passwort')
+		}
+	]);
+
+	await expect(page.getByRole('alert')).toContainText('passwortgeschützt');
+	await expect(page.getByRole('alert')).toContainText('Passwort entfernen');
+	expect(pageErrors).toEqual([]);
+});
+
+test('merge hands the merged PDF over to pagination', async ({ page }) => {
+	const pageErrors = trackPageErrors(page);
+	await page.goto('/tools/merge');
+	await dropFiles(page, pdfDropzone(page), [
+		{ name: 'eins.pdf', mimeType: 'application/pdf', buffer: await createPdf(1, 'Eins') },
+		{ name: 'zwei.pdf', mimeType: 'application/pdf', buffer: await createPdf(2, 'Zwei') }
+	]);
+
+	await page.getByRole('button', { name: 'Zusammenfügen & paginieren' }).click();
+	await expect(page).toHaveURL(/\/tools\/pagination$/);
+	await expect(page.getByText('Seite 1 von 3')).toBeVisible({ timeout: 15_000 });
+
+	const bytes = await downloadPaginated(page, /^zusammengefuegt_paginiert\.pdf$/);
+	const output = await PDFDocument.load(bytes);
+	expect(output.getPageCount()).toBe(3);
+	expect(getPageText(output, 0)).toContain('Bl. 1');
+	expect(getPageText(output, 1)).toContain('Bl. 2');
+	expect(getPageText(output, 2)).toContain('Bl. 3');
+	expect(pageErrors).toEqual([]);
+});

tests/e2e/stamp.spec.ts

@@ -1,4 +1,6 @@
 import { expect, test } from '@playwright/test';
+import { unzipSync } from 'fflate';
+import { readFile } from 'node:fs/promises';
 import { PDFDocument } from 'pdf-lib';
 import {
 	createEncryptedPdf,
@@ -29,8 +31,10 @@ test('stamp presets fill the editable text and EILT is applied to every page', a
 	await expect(page.getByTestId('stamp-preview')).toContainText('EILT');
 	await expect(page.getByTestId('stamp-preview')).not.toHaveCSS('transform', 'none');
 
+	await page.getByRole('button', { name: 'Stempel anwenden', exact: true }).click();
+	await expect(page.getByText('Fertig ✓')).toBeVisible({ timeout: 20_000 });
 	const downloadPromise = page.waitForEvent('download');
-	await page.getByRole('button', { name: 'Stempel anwenden & herunterladen' }).click();
+	await page.getByRole('button', { name: 'akte.pdf herunterladen' }).click();
 	const outputBytes = await expectPdfDownload(await downloadPromise, /^akte_stempel\.pdf$/);
 	const output = await PDFDocument.load(outputBytes);
 	expect(output.getPageCount()).toBe(3);
@@ -58,8 +62,10 @@ test('stamp custom text adds a German date and only changes selected pages', asy
 	await page.getByRole('checkbox', { name: 'Auf alle Seiten anwenden' }).uncheck();
 	await page.getByRole('button', { name: /Seite 2/ }).click();
 
+	await page.getByRole('button', { name: 'Stempel anwenden', exact: true }).click();
+	await expect(page.getByText('Fertig ✓')).toBeVisible({ timeout: 20_000 });
 	const downloadPromise = page.waitForEvent('download');
-	await page.getByRole('button', { name: 'Stempel anwenden & herunterladen' }).click();
+	await page.getByRole('button', { name: 'auswahl.pdf herunterladen' }).click();
 	const outputBytes = await expectPdfDownload(await downloadPromise, /^auswahl_stempel\.pdf$/);
 	const output = await PDFDocument.load(outputBytes);
 	expect(output.getPageCount()).toBe(3);
@@ -89,8 +95,10 @@ test('stamp uses an image instead of text and makes the border optional', async
 		page.getByRole('checkbox', { name: 'Rahmen um das Bild anzeigen' })
 	).not.toBeChecked();
 
+	await page.getByRole('button', { name: 'Stempel anwenden', exact: true }).click();
+	await expect(page.getByText('Fertig ✓')).toBeVisible({ timeout: 20_000 });
 	const downloadPromise = page.waitForEvent('download');
-	await page.getByRole('button', { name: 'Stempel anwenden & herunterladen' }).click();
+	await page.getByRole('button', { name: 'bildakte.pdf herunterladen' }).click();
 	const outputBytes = await expectPdfDownload(await downloadPromise, /^bildakte_stempel\.pdf$/);
 	const output = await PDFDocument.load(outputBytes);
 	expect(output.getPageCount()).toBe(2);
@@ -103,8 +111,18 @@ test('stamp uses an image instead of text and makes the border optional', async
 
 	await page.getByRole('checkbox', { name: 'Rahmen um das Bild anzeigen' }).check();
 	await expect(page.getByTestId('stamp-preview')).toHaveCSS('border-style', 'solid');
+
+	// Re-add the file so the changed option applies to a fresh pending row.
+	await page.getByRole('button', { name: 'bildakte.pdf entfernen' }).click();
+	await dropFiles(page, pdfDropzone(page), [
+		{ name: 'bildakte.pdf', mimeType: 'application/pdf', buffer: await createPdf(2, 'Bild') }
+	]);
+	await expect(page.getByTestId('stamp-preview').locator('img')).toBeVisible();
+
+	await page.getByRole('button', { name: 'Stempel anwenden', exact: true }).click();
+	await expect(page.getByText('Fertig ✓')).toBeVisible({ timeout: 20_000 });
 	const borderedDownloadPromise = page.waitForEvent('download');
-	await page.getByRole('button', { name: 'Stempel anwenden & herunterladen' }).click();
+	await page.getByRole('button', { name: 'bildakte.pdf herunterladen' }).click();
 	const borderedBytes = await expectPdfDownload(
 		await borderedDownloadPromise,
 		/^bildakte_stempel\.pdf$/
@@ -120,6 +138,45 @@ test('stamp uses an image instead of text and makes the border optional', async
 	expect(pageErrors).toEqual([]);
 });
 
+test('stamp batch applies to every file and bundles results in one ZIP', async ({ page }) => {
+	const pageErrors = trackPageErrors(page);
+	await page.goto('/tools/stamp');
+	await dropFiles(page, pdfDropzone(page), [
+		{ name: 'eins.pdf', mimeType: 'application/pdf', buffer: await createPdf(1, 'Eins') },
+		{ name: 'zwei.pdf', mimeType: 'application/pdf', buffer: await createPdf(2, 'Zwei') },
+		{
+			name: 'kaputt.pdf',
+			mimeType: 'application/pdf',
+			buffer: Buffer.from('kein gueltiges PDF')
+		},
+		{
+			name: 'geschuetzt.pdf',
+			mimeType: 'application/pdf',
+			buffer: await createEncryptedPdf(1, 'Geschützt', 'test-passwort')
+		}
+	]);
+
+	await expect(page.getByText('Dateien (4)')).toBeVisible();
+	// With several files the stamp is applied to every page and no preview is loaded.
+	await expect(page.getByRole('checkbox', { name: 'Auf alle Seiten anwenden' })).toHaveCount(0);
+	await expect(page.getByRole('heading', { name: 'Vorschau' })).toHaveCount(0);
+
+	await page.getByRole('button', { name: 'Stempel anwenden', exact: true }).click();
+	await expect(page.getByText('Fertig ✓')).toHaveCount(2, { timeout: 30_000 });
+	await expect(page.getByText('Fehler')).toHaveCount(2);
+	await expect(page.getByText('Dieses PDF ist passwortgeschützt')).toBeVisible();
+
+	const downloadPromise = page.waitForEvent('download');
+	await page.getByRole('button', { name: 'Alle herunterladen' }).click();
+	const download = await downloadPromise;
+	expect(download.suggestedFilename()).toMatch(/^stempel_\d{4}-\d{2}-\d{2}\.zip$/);
+	const zipPath = await download.path();
+	expect(zipPath).not.toBeNull();
+	const entries = Object.keys(unzipSync(new Uint8Array(await readFile(zipPath!))));
+	expect(entries.sort()).toEqual(['eins_stempel.pdf', 'zwei_stempel.pdf']);
+	expect(pageErrors).toEqual([]);
+});
+
 test('stamp explains how to handle a password-protected PDF', async ({ page }) => {
 	const pageErrors = trackPageErrors(page);
 	await page.goto('/tools/stamp');

tests/e2e/start-page.spec.ts

@@ -12,6 +12,7 @@ test('start page exposes only working tools and forwards a dropped ZIP to beA',
 	await page.goto('/');
 	await expect(page.getByRole('heading', { name: 'Werkzeugkasten für beA' })).toBeVisible();
 	await expect(page.getByRole('link', { name: /Stempeln/ })).toBeVisible();
+	await expect(page.getByRole('link', { name: /Paginieren/ })).toBeVisible();
 	await expect(page.getByRole('link', { name: /Signieren/ })).toHaveCount(0);
 
 	await dropFiles(page, 'window', [

tests/e2e/tools.spec.ts

@@ -0,0 +1,16 @@
+import { expect, test } from '@playwright/test';
+import { tools } from '../../src/lib/tools';
+
+/**
+ * The tool registry, its icon map, the route files and the page headings all
+ * live in different files. This catches the case where one of them drifts and a
+ * registered tool 404s or renders under a different title.
+ */
+for (const tool of tools) {
+	test(`the registry entry "${tool.title}" renders at /tools/${tool.slug}`, async ({ page }) => {
+		const response = await page.goto(`/tools/${tool.slug}`);
+
+		expect(response?.status()).toBe(200);
+		await expect(page.getByRole('heading', { level: 1, name: tool.title })).toBeVisible();
+	});
+}

tests/unit/exhibit-naming.spec.ts

@@ -0,0 +1,83 @@
+import { expect, test } from '@playwright/test';
+import {
+	DEFAULT_EXHIBIT_PREFIX,
+	MAX_EXHIBIT_PREFIX_LENGTH,
+	MAX_EXHIBIT_START_NUMBER,
+	MIN_EXHIBIT_START_NUMBER,
+	buildExhibitFileName,
+	buildExhibitLabel,
+	buildExhibitPrefixSlug,
+	getExhibitNumberWidth,
+	normalizeExhibitPrefix,
+	normalizeExhibitStartNumber
+} from '../../src/lib/exhibit-naming';
+
+test('the prefix is trimmed and capped', () => {
+	expect(normalizeExhibitPrefix('  Anlage K  ')).toBe('Anlage K');
+	expect(normalizeExhibitPrefix('')).toBe('');
+	expect(normalizeExhibitPrefix('A'.repeat(MAX_EXHIBIT_PREFIX_LENGTH + 10))).toHaveLength(
+		MAX_EXHIBIT_PREFIX_LENGTH
+	);
+});
+
+test('labels use one space and never pad the number', () => {
+	expect(buildExhibitLabel('Anlage K', 6)).toBe('Anlage K 6');
+	expect(buildExhibitLabel('  Anlage  ', 1)).toBe('Anlage 1');
+	expect(buildExhibitLabel('Anlage', 98)).toBe('Anlage 98');
+});
+
+test('the padding width follows the highest assigned number', () => {
+	expect(getExhibitNumberWidth(9)).toBe(2);
+	expect(getExhibitNumberWidth(99)).toBe(2);
+	expect(getExhibitNumberWidth(100)).toBe(3);
+	expect(getExhibitNumberWidth(1000)).toBe(4);
+});
+
+test('file names prefix the number and keep the original base name', () => {
+	expect(
+		buildExhibitFileName({
+			prefix: 'Anlage K',
+			number: 6,
+			highestNumber: 8,
+			originalName: 'Klageschrift.pdf'
+		})
+	).toBe('Anlage_K_06_Klageschrift.pdf');
+
+	expect(
+		buildExhibitFileName({
+			prefix: 'Anlage K',
+			number: 98,
+			highestNumber: 100,
+			originalName: 'Anlage.PDF'
+		})
+	).toBe('Anlage_K_098_Anlage.pdf');
+});
+
+test('unsafe characters never reach the file name', () => {
+	expect(
+		buildExhibitFileName({
+			prefix: 'Anlage K/1',
+			number: 1,
+			highestNumber: 1,
+			originalName: 'a:b*c?.pdf'
+		})
+	).toBe('Anlage_K1_01_abc.pdf');
+});
+
+test('an empty prefix falls back to the default slug', () => {
+	expect(buildExhibitPrefixSlug('   ')).toBe(DEFAULT_EXHIBIT_PREFIX);
+	expect(
+		buildExhibitFileName({ prefix: '', number: 3, highestNumber: 3, originalName: 'x.pdf' })
+	).toBe('Anlage_03_x.pdf');
+});
+
+test('the start number is clamped and survives an empty field', () => {
+	expect(normalizeExhibitStartNumber(1)).toBe(1);
+	expect(normalizeExhibitStartNumber(0)).toBe(MIN_EXHIBIT_START_NUMBER);
+	expect(normalizeExhibitStartNumber(-5)).toBe(MIN_EXHIBIT_START_NUMBER);
+	expect(normalizeExhibitStartNumber(6.6)).toBe(7);
+	expect(normalizeExhibitStartNumber(undefined)).toBe(1);
+	expect(normalizeExhibitStartNumber(null)).toBe(1);
+	expect(normalizeExhibitStartNumber('')).toBe(1);
+	expect(normalizeExhibitStartNumber(1_000_000)).toBe(MAX_EXHIBIT_START_NUMBER);
+});

tests/unit/pdf-errors.spec.ts

@@ -0,0 +1,40 @@
+import { expect, test } from '@playwright/test';
+import {
+	ENCRYPTED_PDF_MESSAGE,
+	TextOverlayError,
+	classifyPdfError,
+	pdfLoadErrorMessage,
+	pdfProcessingErrorMessage
+} from '../../src/lib/pdf-errors';
+
+const encryptedError = () =>
+	new Error(
+		'Input document to `PDFDocument.load` is encrypted. You can use `PDFDocument.load(..., { ignoreEncryption: true })`'
+	);
+
+test('overlay failures keep their own copy', () => {
+	const error = new TextOverlayError('Der Text ist zu lang.');
+
+	expect(classifyPdfError(error)).toBe('text-overlay');
+	expect(pdfProcessingErrorMessage(error, 'Fallback')).toBe('Der Text ist zu lang.');
+	expect(pdfLoadErrorMessage(error)).toBe('Der Text ist zu lang.');
+});
+
+test('encrypted PDFs map to the shared password hint', () => {
+	expect(classifyPdfError(encryptedError())).toBe('encrypted');
+	expect(pdfProcessingErrorMessage(encryptedError(), 'Fallback')).toBe(ENCRYPTED_PDF_MESSAGE);
+	expect(pdfLoadErrorMessage(encryptedError())).toBe(ENCRYPTED_PDF_MESSAGE);
+});
+
+test('unknown failures fall back to the caller copy', () => {
+	const error = new Error('Invalid PDF structure');
+
+	expect(classifyPdfError(error)).toBe('unknown');
+	expect(pdfProcessingErrorMessage(error, 'Fehler beim Drehen der Seiten.')).toBe(
+		'Fehler beim Drehen der Seiten.'
+	);
+	expect(pdfLoadErrorMessage(error, 'Eigene Meldung.')).toBe('Eigene Meldung.');
+	expect(pdfLoadErrorMessage(error)).toContain('PDF konnte nicht geladen werden');
+	// Tool-specific copy must never be overridden by the classification.
+	expect(pdfProcessingErrorMessage('boom', 'Eigene Meldung.')).toBe('Eigene Meldung.');
+});

tests/unit/pdf-pagination.spec.ts

@@ -0,0 +1,131 @@
+import { expect, test } from '@playwright/test';
+import { PDFDocument } from 'pdf-lib';
+import { TextOverlayError } from '../../src/lib/pdf-errors';
+import type { OverlayPosition } from '../../src/lib/pdf-overlay';
+import {
+	MAX_FREE_TEXT_LENGTH,
+	PAGINATION_FORMATS,
+	buildPaginationLabel,
+	normalizeFreeText,
+	normalizeStartNumber,
+	paginatePdf,
+	type PaginationFormat,
+	type PaginationOptions,
+	type PaginationTextScope
+} from '../../src/lib/pdf-pagination';
+import { getPageTextValues } from '../e2e/helpers';
+
+const labelOptions = (
+	overrides: Partial<{
+		startNumber: number;
+		freeText: string;
+		textScope: PaginationTextScope;
+		format: PaginationFormat;
+	}> = {}
+) => ({
+	startNumber: 1,
+	freeText: '',
+	textScope: 'all' as const,
+	format: 'blatt' as const,
+	...overrides
+});
+
+const paginationOptions = (overrides: Partial<PaginationOptions> = {}): PaginationOptions => ({
+	startNumber: 1,
+	freeText: '',
+	textScope: 'all',
+	format: 'blatt',
+	position: 'bottom-center' as OverlayPosition,
+	fontSize: 11,
+	...overrides
+});
+
+/** Blank pages, so the stamped sheet number is the only text in the output. */
+const createPdf = async (pageCount: number, size: [number, number] = [420, 594]) => {
+	const document = await PDFDocument.create();
+
+	for (let index = 0; index < pageCount; index += 1) document.addPage(size);
+
+	return new Uint8Array(await document.save());
+};
+
+test('every format is offered with a rendered example label', () => {
+	expect(PAGINATION_FORMATS.map((format) => format.value)).toEqual([
+		'blatt',
+		'seite',
+		's',
+		'nummer'
+	]);
+	expect(PAGINATION_FORMATS.map((format) => format.label)).toEqual([
+		'Bl. 1',
+		'Seite 1',
+		'S. 1',
+		'1'
+	]);
+});
+
+test('label combines the free text with the ascending sheet number', () => {
+	expect(buildPaginationLabel(0, labelOptions({ startNumber: 26 }))).toBe('Bl. 26');
+	expect(buildPaginationLabel(2, labelOptions({ startNumber: 26 }))).toBe('Bl. 28');
+	expect(buildPaginationLabel(0, labelOptions({ freeText: '  123 Ja 60/26 ' }))).toBe(
+		'123 Ja 60/26, Bl. 1'
+	);
+	expect(buildPaginationLabel(0, labelOptions({ format: 'seite', startNumber: 6 }))).toBe(
+		'Seite 6'
+	);
+	expect(buildPaginationLabel(0, labelOptions({ format: 's', startNumber: 6 }))).toBe('S. 6');
+	expect(buildPaginationLabel(0, labelOptions({ format: 'nummer', startNumber: 6 }))).toBe('6');
+	// No leading zeros — a start number of 6 is not "06".
+	expect(buildPaginationLabel(0, labelOptions({ startNumber: 6 }))).toBe('Bl. 6');
+});
+
+test('the free text is dropped on later pages for the first-page scope', () => {
+	const options = labelOptions({ freeText: 'AZ 7/26', textScope: 'first', format: 's' });
+
+	expect(buildPaginationLabel(0, options)).toBe('AZ 7/26, S. 1');
+	expect(buildPaginationLabel(1, options)).toBe('S. 2');
+});
+
+test('start number and free text are normalised at the boundary', () => {
+	expect(normalizeStartNumber(0)).toBe(1);
+	expect(normalizeStartNumber(-5)).toBe(1);
+	expect(normalizeStartNumber(2.6)).toBe(3);
+	expect(normalizeStartNumber(Number.NaN)).toBe(1);
+	expect(normalizeStartNumber(1_000_000)).toBe(99_999);
+
+	expect(normalizeFreeText('  123 Ja 60/26  ')).toBe('123 Ja 60/26');
+	expect(normalizeFreeText('x'.repeat(90))).toHaveLength(MAX_FREE_TEXT_LENGTH);
+});
+
+test('paginatePdf stamps each page exactly once', async () => {
+	const output = await paginatePdf(
+		await createPdf(3),
+		paginationOptions({ startNumber: 26, freeText: '123 Ja 60/26' })
+	);
+	const document = await PDFDocument.load(output);
+
+	expect(document.getPageCount()).toBe(3);
+	expect(getPageTextValues(document, 0)).toEqual(['123 Ja 60/26, Bl. 26']);
+	expect(getPageTextValues(document, 1)).toEqual(['123 Ja 60/26, Bl. 27']);
+	expect(getPageTextValues(document, 2)).toEqual(['123 Ja 60/26, Bl. 28']);
+});
+
+test('paginatePdf honours the first-page-only scope', async () => {
+	const output = await paginatePdf(
+		await createPdf(2),
+		paginationOptions({ freeText: 'AZ 7/26', textScope: 'first', format: 'nummer' })
+	);
+	const document = await PDFDocument.load(output);
+
+	expect(getPageTextValues(document, 0)).toEqual(['AZ 7/26, 1']);
+	expect(getPageTextValues(document, 1)).toEqual(['2']);
+});
+
+test('a label that cannot fit at the minimum font size fails loudly', async () => {
+	await expect(
+		paginatePdf(
+			await createPdf(1, [120, 160]),
+			paginationOptions({ freeText: 'x'.repeat(MAX_FREE_TEXT_LENGTH), fontSize: 18 })
+		)
+	).rejects.toBeInstanceOf(TextOverlayError);
+});

tests/unit/pdf-text-overlay.spec.ts

@@ -0,0 +1,133 @@
+import { expect, test } from '@playwright/test';
+import { degrees, PDFDocument, StandardFonts, rgb } from 'pdf-lib';
+import { TextOverlayError } from '../../src/lib/pdf-errors';
+import {
+	TEXT_OVERLAY_MARGIN,
+	drawTextOverlay,
+	getRotatedBoxPlacement
+} from '../../src/lib/pdf-text-overlay';
+import { getPageText, getPageTextAngle, getPageTextMatrix } from '../e2e/helpers';
+
+const PAGE_WIDTH = 420;
+const PAGE_HEIGHT = 594;
+const MARGIN = 28;
+
+/**
+ * Maps a point from default user space to the displayed page. Viewers rotate the
+ * content clockwise by `/Rotate`, so this is the forward transformation.
+ */
+const toVisualPoint = (
+	point: { x: number; y: number },
+	rotation: number,
+	width: number,
+	height: number
+) => {
+	switch (rotation) {
+		case 90:
+			return { x: point.y, y: width - point.x };
+		case 180:
+			return { x: width - point.x, y: height - point.y };
+		case 270:
+			return { x: height - point.y, y: point.x };
+		default:
+			return point;
+	}
+};
+
+const createPageWithMark = async (rotation: number) => {
+	const document = await PDFDocument.create();
+	const font = await document.embedFont(StandardFonts.Helvetica);
+	const page = document.addPage([PAGE_WIDTH, PAGE_HEIGHT]);
+	page.setRotation(degrees(rotation));
+	drawTextOverlay(page, {
+		font,
+		text: 'Bl. 1',
+		size: 11,
+		color: rgb(0.1, 0.1, 0.1),
+		position: 'bottom-center',
+		margin: MARGIN,
+		compensatePageRotation: true
+	});
+
+	return PDFDocument.load(await document.save());
+};
+
+for (const rotation of [0, 90, 180, 270]) {
+	test(`bottom-center mark stays at the visual bottom on a /Rotate ${rotation} page`, async () => {
+		const output = await createPageWithMark(rotation);
+		const matrix = getPageTextMatrix(output, 0);
+		const visualWidth = rotation % 180 === 0 ? PAGE_WIDTH : PAGE_HEIGHT;
+		const origin = toVisualPoint({ x: matrix.x, y: matrix.y }, rotation, PAGE_WIDTH, PAGE_HEIGHT);
+
+		// Horizontally centred on the displayed page.
+		expect(Math.abs(origin.x - visualWidth / 2)).toBeLessThan(30);
+		// Close to the bottom margin (the baseline sits a few points above it).
+		expect(origin.y).toBeGreaterThan(MARGIN - 2);
+		expect(origin.y).toBeLessThan(MARGIN + 20);
+		// The glyphs read horizontally: the drawn angle cancels the page rotation.
+		expect(Math.round(getPageTextAngle(matrix))).toBe(rotation);
+		expect(getPageText(output, 0)).toBe('Bl. 1');
+	});
+}
+
+test('a mark that does not fit raises a TextOverlayError instead of shrinking forever', async () => {
+	const document = await PDFDocument.create();
+	const font = await document.embedFont(StandardFonts.Helvetica);
+	const page = document.addPage([120, 160]);
+
+	expect(() =>
+		drawTextOverlay(page, {
+			font,
+			text: 'Ein sehr langer Stempeltext, der nicht auf die Seite passt',
+			size: 18,
+			color: rgb(0, 0, 0),
+			position: 'bottom-center',
+			margin: MARGIN,
+			framed: true
+		})
+	).toThrow(TextOverlayError);
+});
+
+test('characters the standard font cannot encode are reported as such', async () => {
+	const document = await PDFDocument.create();
+	const font = await document.embedFont(StandardFonts.Helvetica);
+	const page = document.addPage([PAGE_WIDTH, PAGE_HEIGHT]);
+
+	let thrown: unknown;
+	try {
+		drawTextOverlay(page, {
+			font,
+			text: 'Beschluss \u{1F600}',
+			size: 11,
+			color: rgb(0, 0, 0),
+			position: 'top-right',
+			margin: MARGIN
+		});
+	} catch (error) {
+		thrown = error;
+	}
+
+	expect(thrown).toBeInstanceOf(TextOverlayError);
+	expect((thrown as Error).message).toContain('nicht dargestellt werden');
+});
+
+test('a rotated mark keeps its bounding box inside the page', async () => {
+	const boxWidth = 200;
+	const boxHeight = 40;
+
+	for (const angle of [0, 45, 90, 135]) {
+		const placement = getRotatedBoxPlacement(
+			PAGE_WIDTH,
+			PAGE_HEIGHT,
+			boxWidth,
+			boxHeight,
+			'bottom-center',
+			angle,
+			TEXT_OVERLAY_MARGIN
+		);
+
+		expect(placement.x).toBeGreaterThanOrEqual(TEXT_OVERLAY_MARGIN - 0.001);
+		expect(placement.y).toBeGreaterThanOrEqual(TEXT_OVERLAY_MARGIN - 0.001);
+		expect(placement).not.toHaveProperty('cosine');
+	}
+});

tests/unit/pending-files.spec.ts

@@ -0,0 +1,29 @@
+import { expect, test } from '@playwright/test';
+import {
+	clearPendingFiles,
+	queuePendingFiles,
+	takePendingFiles
+} from '../../src/lib/pending-files';
+
+const pdf = () => new File(['%PDF-1.7'], 'akte.pdf', { type: 'application/pdf' });
+const zip = () => new File(['PK'], 'archiv.zip', { type: 'application/zip' });
+
+test.beforeEach(() => clearPendingFiles());
+
+test('a target only receives the files queued for it', () => {
+	queuePendingFiles([zip()], 'bea');
+	queuePendingFiles([pdf()], 'pagination');
+
+	const paginationFiles = takePendingFiles('pagination');
+
+	expect(paginationFiles.map((file) => file.name)).toEqual(['akte.pdf']);
+	// The beA handoff must survive a pagination visit instead of being dropped.
+	expect(takePendingFiles('bea').map((file) => file.name)).toEqual(['archiv.zip']);
+});
+
+test('taking a target clears only that target', () => {
+	queuePendingFiles([pdf(), pdf()], 'pagination');
+
+	expect(takePendingFiles('pagination')).toHaveLength(2);
+	expect(takePendingFiles('pagination')).toHaveLength(0);
+});