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

frontend/src/lib/components/TranscriptionEditView.svelte.spec.ts

@@ -49,6 +49,11 @@ function renderView(overrides: Record<string, unknown> = {}, service = createCon
 	};
 }
 
+const unreviewedBlock1 = { ...block1, reviewed: false };
+const unreviewedBlock2 = { ...block2, reviewed: false };
+const reviewedBlock1 = { ...block1, reviewed: true };
+const reviewedBlock2 = { ...block2, reviewed: true };
+
 describe('TranscriptionEditView — rendering', () => {
 	it('renders blocks in sort order', async () => {
 		renderView();
@@ -269,3 +274,61 @@ describe('TranscriptionEditView — review progress counter', () => {
 		await expect.element(page.getByText(/geprüft/)).not.toBeInTheDocument();
 	});
 });
+
+// ─── Bulk mark all as reviewed ────────────────────────────────────────────────
+
+describe('TranscriptionEditView — mark all reviewed', () => {
+	it('shows "Alle als fertig markieren" button when onMarkAllReviewed is provided and blocks are unreviewed', async () => {
+		renderView({
+			blocks: [unreviewedBlock1, unreviewedBlock2],
+			onMarkAllReviewed: vi.fn().mockResolvedValue(undefined)
+		});
+		await expect
+			.element(page.getByRole('button', { name: /Alle als fertig markieren/ }))
+			.toBeInTheDocument();
+	});
+
+	it('does not show "Alle als fertig markieren" button when onMarkAllReviewed is not provided', async () => {
+		renderView({ blocks: [unreviewedBlock1, unreviewedBlock2] });
+		await expect
+			.element(page.getByRole('button', { name: /Alle als fertig markieren/ }))
+			.not.toBeInTheDocument();
+	});
+
+	it('disables button when all blocks are already reviewed', async () => {
+		renderView({
+			blocks: [reviewedBlock1, reviewedBlock2],
+			onMarkAllReviewed: vi.fn().mockResolvedValue(undefined)
+		});
+		await expect
+			.element(page.getByRole('button', { name: /Alle als fertig markieren/ }))
+			.toBeDisabled();
+	});
+
+	it('calls onMarkAllReviewed exactly once when button is clicked', async () => {
+		const onMarkAllReviewed = vi.fn().mockResolvedValue(undefined);
+		renderView({
+			blocks: [unreviewedBlock1, unreviewedBlock2],
+			onMarkAllReviewed
+		});
+
+		await page.getByRole('button', { name: /Alle als fertig markieren/ }).click();
+		await vi.waitFor(() => expect(onMarkAllReviewed).toHaveBeenCalledTimes(1));
+	});
+
+	it('disables button while operation is in-flight', async () => {
+		let resolveMarkAll!: () => void;
+		const onMarkAllReviewed = vi
+			.fn()
+			.mockReturnValue(new Promise<void>((r) => (resolveMarkAll = r)));
+		renderView({
+			blocks: [unreviewedBlock1, unreviewedBlock2],
+			onMarkAllReviewed
+		});
+
+		const btn = page.getByRole('button', { name: /Alle als fertig markieren/ });
+		await btn.click();
+		await expect.element(btn).toBeDisabled();
+		resolveMarkAll();
+	});
+});