Dagger can't run on the bare nix runner (needs container runtime).
Used nix eval directly instead.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
## Summary
- Add `dagger` to `hostPackages` for the ringtail nix-container-builder runner
- Needed for `dagger call nix-version` fallback in the nix build workflow (authentik)
- `hostPackages` is scoped to the runner's systemd unit PATH, not system-wide
- Marks `install-dagger-on-nix-runner` Mikado card complete
## Deployment and Testing
- [ ] Merge, then `mise run provision-ringtail`
- [ ] `mise run container-build-and-release authentik` to verify nix build succeeds
Reviewed-on: https://forge.ops.eblu.me/eblume/blumeops/pulls/234
## Summary
- New Mikado card: the ringtail nix-container-builder runner lacks dagger, which the nix workflow needs for `dagger call nix-version` (authentik version extraction fallback)
- Re-opens `adopt-commit-based-container-tags` with this new prerequisite
- All other containers (11 Dockerfile-only, nettest + ntfy with nix) build fine — only authentik's nix build is blocked
## Deployment and Testing
- Docs only, no deployment needed
Reviewed-on: https://forge.ops.eblu.me/eblume/blumeops/pulls/233
