debug: add verbose logging for Google Auth config issues

backend/routers/auth.py

@@ -93,8 +93,13 @@ async def social_login(request: Request, data: schemas.SocialLogin):
 
     # 1. Verify token if provider is Google
     if data.provider == 'google':
+        print(f"DEBUG: Social Login attempt. id_token library available: {id_token is not None}")
+        print(f"DEBUG: config.GOOGLE_CLIENT_ID exists: {bool(config.GOOGLE_CLIENT_ID)}")
+        print(f"DEBUG: config.GOOGLE_CLIENT_ID value: {config.GOOGLE_CLIENT_ID}")
+        
         if not id_token or not config.GOOGLE_CLIENT_ID:
-            raise HTTPException(status_code=500, detail="Google Auth not configured on server")
+            msg = f"Config error: id_token_lib={id_token is not None}, client_id_set={bool(config.GOOGLE_CLIENT_ID)}"
+            raise HTTPException(status_code=500, detail=f"Google Auth not configured on server ({msg})")
         
         try:
             # Verify the ID token