When using trusted email header authentication, properly sign out the user
when the logged-in user's email doesn't match the trusted email header value.
This ensures proper session cleanup when the OAuth server changes the
authenticated user.
- Add response parameter to get_current_user function
- Delete JWT token cookie on email mismatch
- Delete OAuth token cookie if present
- Force re-authentication with 401 error
When using trusted email header authentication, verify that the logged-in user's
email matches the value in the header. This prevents session conflicts when the
OAuth server changes the authenticated user.
- Move trusted email verification after user existence check
- Raise 401 if email mismatch is detected
- Only perform verification when WEBUI_AUTH_TRUSTED_EMAIL_HEADER is enabled
