self_update_service compares registry version tags against APP_VERSION
to detect a newer release; with only :latest pushed, it always reported
"No version tags found" and the update pill never appeared. Read the
version from backend/version.py and push it as an extra tag for all
three images.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016pMmFFkdfxkoYjcEcpZTa5
Image references still pointed at the old server (10.10.6.10:3020/menzelj);
menzelj was never a valid namespace there either, the actual account is
menzeljonas. Also adds .gitea/workflows/ci.yml to build and push
backend, frontend and agent on push to main.