Fix async generator exception handling in get_optional_database_session

src/server/utils/dependencies.py

@@ -170,7 +170,12 @@ async def get_optional_database_session() -> AsyncGenerator:
         from src.server.database import get_db_session
         
         async with get_db_session() as session:
-            yield session
+            try:
+                yield session
+            except Exception:
+                # Re-raise to let FastAPI handle it properly
+                # This prevents "generator didn't stop after athrow()" error
+                raise
     except (ImportError, RuntimeError):
         # Database not available - yield None
         yield None