feat(transcription): add bulk "Alle als fertig markieren" action to transcription panel

Adds a single-transaction backend endpoint PUT /api/documents/{id}/transcription-blocks/review-all
that marks all blocks as reviewed atomically. Emits N individual BLOCK_REVIEWED audit events (one
per previously-unreviewed block). The frontend button is disabled (not hidden) when all blocks are
already reviewed, and shows a spinner during the operation.

Closes #345

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

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();
+	});
+});