feat(transcription): add "Alle als fertig markieren" bulk action (#345) (#352)

## Summary

Implements the bulk "Alle als fertig markieren" action for the transcription panel requested in #345.

### Backend

- Added `PUT /api/documents/{documentId}/transcription-blocks/review-all` endpoint to `TranscriptionBlockController`, guarded with `@RequirePermission(Permission.WRITE_ALL)`
- Added `markAllBlocksReviewed(UUID documentId, UUID userId)` to `TranscriptionService` — `@Transactional`, single DB round-trip via `blockRepository.saveAll()`, emits one `BLOCK_REVIEWED` audit event per previously-unreviewed block
- Returns full updated block list (same shape as `listBlocks`) for a clean frontend update pass
- 5 new `TranscriptionServiceTest` unit tests (idempotency, audit events, empty document)
- 5 new `TranscriptionBlockControllerTest` `@WebMvcTest` tests (401, 403, 200 happy path, 200 empty, 401 user not found)
- All 68 backend tests pass

### Frontend

- Added `onMarkAllReviewed?: () => Promise<void>` prop to `TranscriptionEditView` (optional, consistent with `onTriggerOcr` pattern)
- Button placed in sticky progress header, right-aligned next to `reviewedCount / totalCount geprüft`
- Button is **disabled** (not hidden) when all blocks are already reviewed — `title="Alle Blöcke sind bereits als fertig markiert"` (Decision 1)
- Loading spinner replaces checkmark icon during operation — always shown (Decision 4, no threshold)
- Handler `markAllReviewed()` added to `documents/[id]/+page.svelte`, wired as `onMarkAllReviewed`
- 5 new `TranscriptionEditView.svelte.spec.ts` Vitest Browser component tests; all 25 tests pass

### Decisions applied

| # | Question | Choice |
|---|---|---|
| 1 | Button when all reviewed | **Disabled** with `title` tooltip |
| 2 | Audit log | **N individual BLOCK_REVIEWED events** (one per unreviewed block) |
| 3 | Atomicity | **All-or-nothing** via `@Transactional` |
| 4 | Loading indicator | **Always show** during operation |

Closes #345

Co-authored-by: Marcel <marcel@familienarchiv>
Reviewed-on: http://heim-nas:3005/marcel/familienarchiv/pulls/352

backend/src/main/java/org/raddatz/familienarchiv/controller/TranscriptionBlockController.java

@@ -90,6 +90,15 @@ public class TranscriptionBlockController {
         return transcriptionService.reviewBlock(documentId, blockId, userId);
     }
 
+    @PutMapping("/review-all")
+    @RequirePermission(Permission.WRITE_ALL)
+    public List<TranscriptionBlock> markAllBlocksReviewed(
+            @PathVariable UUID documentId,
+            Authentication authentication) {
+        UUID userId = requireUserId(authentication);
+        return transcriptionService.markAllBlocksReviewed(documentId, userId);
+    }
+
     @GetMapping("/{blockId}/history")
     @RequirePermission(Permission.READ_ALL)
     public List<TranscriptionBlockVersion> getBlockHistory(

backend/src/main/java/org/raddatz/familienarchiv/service/TranscriptionService.java

@@ -205,6 +205,18 @@ public class TranscriptionService {
         return saved;
     }
 
+    @Transactional
+    public List<TranscriptionBlock> markAllBlocksReviewed(UUID documentId, UUID userId) {
+        List<TranscriptionBlock> blocks = blockRepository.findByDocumentIdOrderBySortOrderAsc(documentId);
+        for (TranscriptionBlock block : blocks) {
+            if (!block.isReviewed()) {
+                block.setReviewed(true);
+                auditService.logAfterCommit(AuditKind.BLOCK_REVIEWED, userId, documentId, null);
+            }
+        }
+        return blockRepository.saveAll(blocks);
+    }
+
     public List<TranscriptionBlockVersion> getBlockHistory(UUID documentId, UUID blockId) {
         getBlock(documentId, blockId);
         return versionRepository.findByBlockIdOrderByChangedAtDesc(blockId);