Frontend:
- Add Companion Agent card to ServerView (status, download links, setup instructions)
- Shows agent connection status, last heartbeat, license key for copy
- Download buttons for Linux/Windows amd64 from Gitea releases
CI/CD:
- Fix build-companion.yml: replace actions/github-script with Gitea API curl
- Inject version from git tag via ldflags (-X main.version)
- Add VERSION variable to Makefile with ldflags injection
- Change main.go version from const to var for ldflags compatibility
Deployment:
- Add systemd service file (deployment/corrosion-companion.service)
- Add .gitignore for bin/ (binaries should come from CI, not repo)
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
