feat: add AI research chatbot with confirmed business tools

backend/tests/browser_server.py

@@ -11,6 +11,7 @@ from app.config import Settings
 from app.main import create_app
 from app.models import Base
 from app.worldquant import WqClient
+from tests.ai_fake import fake_model
 
 TEST_PASSWORD = "browser-test-password"
 
@@ -120,7 +121,9 @@ def create_test_app():
         record = next((r for r in records if path == f"/alphas/{r['id']}"), None)
         return httpx.Response(200, json=record) if record else httpx.Response(404)
 
-    application = create_app(settings, WqClient(settings, transport=httpx.MockTransport(upstream)))
+    application = create_app(
+        settings, WqClient(settings, transport=httpx.MockTransport(upstream)), ai_model_factory=fake_model
+    )
     original_lifespan = application.router.lifespan_context
 
     @asynccontextmanager