fix: await get_session and create_session (async ADK 1.x API)

agents/core-logic/app.py

@@ -52,10 +52,10 @@ class RunResponse(BaseModel):
     response: str
 
 
-def _ensure_session(user_id: str, session_id: str):
-    """Get existing session or create a new one. Handles both ADK 1.x and 2.x."""
+async def _ensure_session(user_id: str, session_id: str):
+    """Await get_session; create if missing or raises."""
     try:
-        session = session_service.get_session(
+        session = await session_service.get_session(
             app_name=APP_NAME,
             user_id=user_id,
             session_id=session_id,
@@ -63,9 +63,9 @@ def _ensure_session(user_id: str, session_id: str):
         if session is not None:
             return session
     except Exception:
-        pass  # session doesn't exist — fall through to create
+        pass
 
-    session = session_service.create_session(
+    session = await session_service.create_session(
         app_name=APP_NAME,
         user_id=user_id,
         session_id=session_id,
@@ -82,7 +82,7 @@ async def health():
 @app.post("/run", response_model=RunResponse)
 async def run(req: RunRequest):
     try:
-        _ensure_session(req.user_id, req.session_id)
+        await _ensure_session(req.user_id, req.session_id)
 
         runner = Runner(
             agent=root_agent,