Fix fastapi-admin login provider binding

app/admin.py

@@ -57,7 +57,9 @@ class EnvCredentialProvider(Provider):
     Tortoise admin models.
     """
 
-    name = "env_credential_provider"
+    # fastapi-admin login templates expect `request.app.login_provider`
+    # to exist for resolving login/logout URLs.
+    name = "login_provider"
     access_token = "access_token"
 
     def __init__(
@@ -82,6 +84,8 @@ class EnvCredentialProvider(Provider):
 
     async def register(self, app: "FastAPIAdmin") -> None:
         await super().register(app)
+        # Keep explicit assignment for compatibility across fastapi-admin versions.
+        app.login_provider = self
         app.get(self.login_path)(self.login_view)
         app.post(self.login_path)(self.login)
         app.get(self.logout_path)(self.logout)