Fix async generator exception handling in database dependencies

src/server/utils/dependencies.py

@@ -124,19 +124,15 @@ async def get_database_session() -> AsyncGenerator:
     """
     try:
         from src.server.database import get_db_session
-        
-        async with get_db_session() as session:
-            try:
-                yield session
-            except Exception:
-                # Re-raise the exception to let FastAPI handle it
-                # This prevents "generator didn't stop after athrow()" error
-                raise
     except ImportError:
         raise HTTPException(
             status_code=status.HTTP_501_NOT_IMPLEMENTED,
             detail="Database functionality not installed"
         )
+    
+    try:
+        async with get_db_session() as session:
+            yield session
     except RuntimeError as e:
         raise HTTPException(
             status_code=status.HTTP_503_SERVICE_UNAVAILABLE,
@@ -168,17 +164,17 @@ async def get_optional_database_session() -> AsyncGenerator:
     """
     try:
         from src.server.database import get_db_session
-        
-        async with get_db_session() as 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
+        return
+    
+    try:
+        async with get_db_session() as session:
+            yield session
+    except (ImportError, RuntimeError):
+        # Database became unavailable - this shouldn't happen but handle it
+        yield None
 
 
 def get_current_user(