merge: integrate backtests with main dataset catalog and sequence migration 0004

backend/tests/browser_server.py

@@ -13,6 +13,7 @@ from app.models import Base
 from app.worldquant import WqClient
 from tests.ai_fake import fake_model
 from tests.backtest_fake import Platform
+from tests.catalog_fake import catalog_response
 
 TEST_PASSWORD = "browser-test-password"
 
@@ -111,6 +112,9 @@ def create_test_app():
             return simulations(request)
         if request.method != "GET":
             raise AssertionError("Browser acceptance attempted an upstream mutation")
+        catalog = catalog_response(request)
+        if catalog is not None:
+            return catalog
         if path == "/users/self":
             return httpx.Response(
                 200,