Fix SSE streaming by hijacking Fastify response

Fastify was buffering the SSE response, causing store progress
to appear stuck. Using reply.hijack() hands off the raw response
so events flush immediately to the client.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/server/routes/search.ts

@@ -66,12 +66,28 @@ export const searchRoutes: FastifyPluginAsync = async (app) => {
       ? stores.split(',').map(Number).filter((n) => !isNaN(n))
       : undefined;
 
-    reply.raw.writeHead(200, {
+    // Hijack the response from Fastify so we can stream SSE directly
+    reply.hijack();
+
+    const res = reply.raw;
+
+    res.writeHead(200, {
       'Content-Type': 'text/event-stream',
-      'Cache-Control': 'no-cache',
+      'Cache-Control': 'no-cache, no-transform',
       'Connection': 'keep-alive',
+      'X-Accel-Buffering': 'no',
     });
 
+    // Send initial comment to establish connection
+    res.write(':ok\n\n');
+
+    const sendEvent = (event: any) => {
+      if (!res.closed) {
+        res.write(`data: ${JSON.stringify(event)}\n\n`);
+      }
+    };
+
+    try {
       await searchStreaming(
         {
           query: q,
@@ -79,11 +95,12 @@ export const searchRoutes: FastifyPluginAsync = async (app) => {
           categoryId: category ? Number(category) : undefined,
           groupId: group ? Number(group) : undefined,
         },
-      (event) => {
-        reply.raw.write(`data: ${JSON.stringify(event)}\n\n`);
-      },
+        sendEvent,
       );
+    } catch (err) {
+      sendEvent({ type: 'done', meta: { query: q, duration: 0, storeCount: 0, totalResults: 0, errors: [{ storeId: 0, storeName: 'System', error: String(err) }] } });
+    }
 
-    reply.raw.end();
+    res.end();
   });
 };