fix scan SSE race: connect before starting scan so no events are missed

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

src/features/scan/ScanPage.tsx

@@ -31,9 +31,8 @@ export function ScanPage() {
 
 	useEffect(() => { load(); }, []);
 
-	// Connect SSE when running
-	useEffect(() => {
-		if (!status?.running) return;
+	const connectSse = () => {
+		esRef.current?.close();
 		const es = new EventSource('/api/scan/events');
 		esRef.current = es;
 
@@ -53,24 +52,42 @@ export function ScanPage() {
 		es.addEventListener('complete', (e) => {
 			const d = JSON.parse(e.data || '{}') as { scanned?: number; errors?: number };
 			es.close();
+			esRef.current = null;
 			setStatusLabel(`Scan complete — ${d.scanned ?? '?'} items, ${d.errors ?? 0} errors`);
 			setStatus((prev) => prev ? { ...prev, running: false } : prev);
 		});
 
 		es.addEventListener('error', () => {
 			es.close();
+			esRef.current = null;
 			setStatusLabel('Scan connection lost — refresh to see current status');
+			setStatus((prev) => prev ? { ...prev, running: false } : prev);
 		});
 
-		return () => es.close();
+		return es;
+	};
+
+	// Reconnect SSE on page load if scan is already running (skip if already connected)
+	useEffect(() => {
+		if (!status?.running || esRef.current) return;
+		connectSse();
+		return () => { esRef.current?.close(); esRef.current = null; };
 	}, [status?.running]);
 
 	const startScan = async () => {
+		setLog([]);
+		setProgressScanned(0);
+		setProgressTotal(0);
+		setErrors(0);
+		setCurrentItem('');
+		setStatusLabel('Scan in progress…');
+		setStatus((prev) => prev ? { ...prev, running: true } : prev);
+
+		// Connect SSE before starting the scan so no events are missed
+		connectSse();
+
 		const limitNum = limit ? Number(limit) : undefined;
 		await api.post('/api/scan/start', limitNum !== undefined ? { limit: limitNum } : {});
-		setStatus((prev) => prev ? { ...prev, running: true } : prev);
-		setStatusLabel('Scan in progress…');
-		setLog([]);
 	};
 
 	const stopScan = async () => {