fix(local-llm): proxy extraction health check through API route

Move extraction service health check from direct browser fetch
(http://localhost:4005/health) to server-side /api/extraction/health
proxy. Eliminates ERR_CONNECTION_REFUSED console errors when the
extraction service is not running locally.

__LOCAL_LLMs/dashboard/src/app/api/extraction/health/route.ts

@@ -0,0 +1,18 @@
+import { NextResponse } from 'next/server';
+
+const EXTRACTION_URL = process.env.EXTRACTION_SERVICE_URL || 'http://localhost:4005';
+
+export async function GET() {
+  try {
+    const res = await fetch(`${EXTRACTION_URL}/health`, {
+      signal: AbortSignal.timeout(2000),
+    });
+    if (res.ok) {
+      const data = await res.json();
+      return NextResponse.json(data);
+    }
+    return NextResponse.json({ status: 'error' });
+  } catch {
+    return NextResponse.json({ status: 'offline' });
+  }
+}

__LOCAL_LLMs/dashboard/src/app/page.tsx

@@ -122,11 +122,9 @@ export default function Dashboard() {
         setMemoryHistory(prev => [...prev.slice(-29), sRes.value.memory.appMemory]);
       }
     }
-    // F15: Check extraction service health (best-effort)
+    // F15: Check extraction service health via server-side proxy (avoids browser CORS/console errors)
     try {
-      const eRes = await fetch('http://localhost:4005/health', {
+      const eRes = await fetch('/api/extraction/health');
-        signal: AbortSignal.timeout(2000),
-      });
       if (eRes.ok) setExtractionHealth(await eRes.json());
       else setExtractionHealth({ status: 'error' });
     } catch {