Auto-update POST goes through Next.js proxy which dies when extracted
files trigger hot-reload. Network drops now transition to restart polling
instead of showing failure. Also adds admin key header and FastAPI error
field fallback. Gitignore updated to protect internal docs.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Former-commit-id: 03162f8a4b7ad8a0f2983f81361df7dba42a8689