- Replace hardcoded legacy Gitea URL in settings.py fallback
- Skip legacy Gitea URL even if saved in DB (treat as unset)
- Track last_response in branch loop so errors report the real HTTP
status code instead of always showing "HTTP unknown"
- Unify 401/403/404 into one "private or not accessible" message
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>