chore: commit remaining maintenance and model changes

backend/src/api/auth.py

@@ -7,6 +7,8 @@
 # @DATA_CONTRACT Input -> OAuth2PasswordRequestForm -> Token, User
 # @INVARIANT All auth endpoints must return consistent error codes.
 # @RELATION DEPENDS_ON -> [is_adfs_configured]
+# @REVIEWED 2026-06-03
+# @TESTED true
 
 from fastapi import APIRouter, Depends, HTTPException, status
 from fastapi.security import OAuth2PasswordRequestForm