v0.0.1-test

port: self-update and metrics-gating (#2)

* port: self-update and metrics-gating

* fix: check error return values

* lint: manager

* fix: self-update security + metrics sync robustness
- TOCTOU: use os.CreateTemp for temp binary to prevent symlink replacement
- data-loss: restore from backup on cross-device copy failure in atomicSwap
- metrics: MetricsEnabled *bool with nil=enabled; collectors default enabled
- refactor hub client 401-retry pattern into doWithKeyRefresh helper
- verify digest and resolve symlinks before exec; skip non-semver silently

* refactor: rename Infrahub → Hyperstack identifiers