feat(frontend): show OcrProgress during OCR job + check status on load

- triggerOcr captures jobId from POST response and shows OcrProgress
- OcrProgress rendered in the transcription panel when ocrJobId is set
- handleOcrDone reloads blocks and annotations when OCR completes
- checkOcrStatus called when entering transcription mode — resumes
  progress display if a job is already running for this document

Refs #226

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

frontend/src/routes/documents/[id]/+page.svelte

@@ -6,6 +6,7 @@ import DocumentViewer from '$lib/components/DocumentViewer.svelte';
 import TranscriptionEditView from '$lib/components/TranscriptionEditView.svelte';
 import TranscriptionReadView from '$lib/components/TranscriptionReadView.svelte';
 import TranscriptionPanelHeader from '$lib/components/TranscriptionPanelHeader.svelte';
+import OcrProgress from '$lib/components/OcrProgress.svelte';
 import type { TranscriptionBlockData } from '$lib/types';
 
 let { data } = $props();
@@ -57,6 +58,7 @@ let activeAnnotationId = $state<string | null>(null);
 let highlightBlockId = $state<string | null>(null);
 let flashAnnotationId = $state<string | null>(null);
 let pdfStripExpanded = $state(false);
+let ocrJobId = $state<string | null>(null);
 
 const prefersReducedMotion = $derived(
 	typeof window !== 'undefined' && window.matchMedia('(prefers-reduced-motion: reduce)').matches
@@ -135,14 +137,21 @@ async function triggerOcr(scriptType: string) {
 			body: JSON.stringify({ scriptType })
 		});
 		if (res.ok) {
-			await loadTranscriptionBlocks();
-			annotationReloadKey++;
+			const data = await res.json();
+			ocrJobId = data.jobId;
 		}
 	} catch (e) {
 		console.error('Failed to trigger OCR:', e);
 	}
 }
 
+async function handleOcrDone() {
+	ocrJobId = null;
+	await loadTranscriptionBlocks();
+	annotationReloadKey++;
+	panelMode = transcriptionBlocks.length > 0 ? 'read' : 'edit';
+}
+
 async function createBlockFromDraw(rect: {
 	x: number;
 	y: number;
@@ -223,12 +232,28 @@ function handleParagraphClick(annotationId: string) {
 	);
 }
 
-// Load blocks when transcribe mode is entered and set default panel mode
+async function checkOcrStatus() {
+	if (!doc?.id) return;
+	try {
+		const res = await fetch(`/api/documents/${doc.id}/ocr-status`);
+		if (res.ok) {
+			const status = await res.json();
+			if (status.status === 'PENDING' || status.status === 'RUNNING') {
+				ocrJobId = status.jobId;
+			}
+		}
+	} catch {
+		// OCR status check is best-effort
+	}
+}
+
+// Load blocks and check OCR status when transcribe mode is entered
 $effect(() => {
 	if (transcribeMode) {
 		loadTranscriptionBlocks().then(() => {
 			panelMode = transcriptionBlocks.length > 0 ? 'read' : 'edit';
 		});
+		checkOcrStatus();
 	}
 });
 
@@ -328,7 +353,11 @@ onMount(() => {
 					onClose={() => (transcribeMode = false)}
 				/>
 				<div class="flex-1 overflow-y-auto">
-					{#if panelMode === 'read'}
+					{#if ocrJobId}
+						<div class="p-4">
+							<OcrProgress jobId={ocrJobId} onDone={handleOcrDone} />
+						</div>
+					{:else if panelMode === 'read'}
 						<TranscriptionReadView
 							blocks={transcriptionBlocks}
 							highlightBlockId={highlightBlockId}