fix: add GCS_MODEL_BUCKET to Settings + google-cloud-storage dependency

- Add GCS_MODEL_BUCKET field to Settings (pydantic-settings was dropping it
  with extra="ignore")
- Use settings.GCS_MODEL_BUCKET directly instead of getattr
- Add google-cloud-storage to requirements.txt for Cloud Run model download

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: mangod12

backend/app/core/config.py

@@ -88,6 +88,9 @@ def emotion_onnx_effective_path(self) -> str:
         int8 = Path(self.EMOTION_ONNX_INT8_PATH)
         return str(int8) if int8.exists() else self.EMOTION_ONNX_PATH
 
+    # ---- GCS model download (Cloud Run) ------------------------------------
+    GCS_MODEL_BUCKET: str = ""
+
     # ---- Whisper STT (local, no paid API) ---------------------------------
     # Model size: tiny | base | small | medium | large
     # "small" balances accuracy + speed on CPU.  Override via WHISPER_MODEL_SIZE env.

backend/app/main.py

@@ -92,11 +92,10 @@ async def lifespan(app: FastAPI):
         log.warning("Database init failed — tables may already exist or DB not ready", error=str(exc))
 
     # 3b. Download ML models from GCS if available (Cloud Run)
-    gcs_bucket = getattr(settings, "GCS_MODEL_BUCKET", "")
-    if gcs_bucket:
+    if settings.GCS_MODEL_BUCKET:
         from app.core.model_downloader import download_models_from_gcs
         model_paths = await asyncio.get_running_loop().run_in_executor(
-            None, download_models_from_gcs, gcs_bucket
+            None, download_models_from_gcs, settings.GCS_MODEL_BUCKET
         )
         # Override config paths with downloaded models
         if "intent_model.onnx" in model_paths:

backend/requirements.txt

@@ -50,6 +50,9 @@ twilio>=9.0.0,<10.0
 jinja2>=3.1.0,<4.0
 aiofiles>=23.0.0,<24.0
 
+# ---- Cloud (GCS model download for Cloud Run) ----------------------------
+google-cloud-storage>=2.14.0,<3.0
+
 # ---- HTTP clients -------------------------------------------------------
 httpx>=0.25.2,<1.0