added mongo auth

backend/config.py

@@ -1,4 +1,4 @@
-from pydantic_settings import BaseSettings # type: ignore
+from pydantic_settings import BaseSettings, SettingsConfigDict  # type: ignore
 from functools import lru_cache
 
 
@@ -9,9 +9,11 @@ class Settings(BaseSettings):
     environment: str = "development"
     frontend_url: str = "http://localhost:8000"
 
-    class Config:
-        env_file = ".env"
-        case_sensitive = False
+    model_config = SettingsConfigDict(
+        env_file=".env",
+        case_sensitive=False,
+        extra="ignore",  # ignore unknown env vars (e.g. VITE_* from root .env)
+    )
 
 
 @lru_cache()