Atlas Cluster Power Recovery (Graceful Shutdown/Startup)

Purpose
- Provide a safe operator flow for planned power events and cold-boot recovery.
- Avoid the Flux/Gitea bootstrap deadlock by using a local bootstrap fallback path.
- Refuse bootstrap when UPS charge is too low, and fall back to fast shutdown if a second outage hits mid-recovery.

Bootstrapping risk to remember
- Flux source is Git over SSH to `scm.bstein.dev` (Gitea).
- Gitea itself is a Flux-managed workload and depends on storage + database.
- Harbor is also critical, but it is not part of the first recovery stage because Harbor currently serves its own runtime images.
- On cold boot, if Flux cannot fetch source before Gitea is up, reconciliation can stall.
- Recovery path: bring control plane and workers up, then locally apply minimal platform stack (`core -> helm -> longhorn -> metallb -> traefik -> vault-csi -> vault-injector -> vault -> postgres -> gitea`), then resume/reconcile Flux. Harbor is a later recovery stage after storage, Vault, Postgres, and Gitea are back.

Script
- `scripts/cluster_power_recovery.sh`
- `scripts/cluster_power_console.sh`
- Modes:
  - `shutdown`
  - `startup`
- Default is dry-run. Add `--execute` to actually perform actions.

Dry-run examples
- Shutdown preview:
  - `scripts/cluster_power_recovery.sh shutdown --skip-etcd-snapshot --skip-drain`
- Startup preview:
  - `scripts/cluster_power_recovery.sh startup`

Execute examples
- Planned shutdown:
  - `scripts/cluster_power_recovery.sh shutdown --execute`
- Planned startup (canonical branch):
  - `scripts/cluster_power_recovery.sh startup --execute --force-flux-branch main`

Manual remote console examples
- From `titan-24` with a local checkout:
  - `~/Development/titan-iac/scripts/cluster_power_console.sh shutdown --execute`
  - `~/Development/titan-iac/scripts/cluster_power_console.sh startup --execute --force-flux-branch main`
- From `titan-db`, if the checkout is not present locally, the console wrapper can delegate to `titan-24`:
  - `~/Development/titan-iac/scripts/cluster_power_console.sh --delegate-host titan-24 shutdown --execute`
  - `~/Development/titan-iac/scripts/cluster_power_console.sh --delegate-host titan-24 startup --execute --force-flux-branch main`

Useful options
- `--control-planes titan-0a,titan-0b,titan-0c`
- `--workers <csv>` (otherwise the script tries API discovery first, then falls back to the static atlas worker inventory)
- `--expected-flux-branch main`
- `--force-flux-branch main`
- `--skip-local-bootstrap` (not recommended for cold-start recovery)
- `--skip-harbor-bootstrap` (skip the Harbor recovery stage if you know Harbor should stay deferred)
- `--min-startup-battery 35`
- `--ups-host ups@localhost`
- `--require-ups-battery`
- `--drain-timeout 180`
- `--emergency-drain-timeout 45`
- `--recovery-state-file ~/.local/state/cluster_power_recovery.state`

Operational notes
- The flow suspends Flux Kustomizations/HelmReleases during shutdown to prevent churn.
- Worker drain is no longer best-effort only. The script now escalates from normal drain, to `--force`, to `--disable-eviction` once the configured timeout is exhausted.
- During startup, if Flux source is not `Ready`, local bootstrap fallback is applied first.
- Longhorn is reconciled before Vault/Postgres/Gitea so storage-backed services are not racing the volume layer.
- Harbor is reconciled after the first critical stateful services. Treat Harbor bootstrap as requiring either cached Harbor runtime images on the scheduled node or a separate bootstrap source for those images.
- The script persists outage state in `~/.local/state/cluster_power_recovery.state` by default. If startup is attempted during an outage window and power becomes unstable again, rerunning startup with insufficient UPS charge will flip into the emergency shutdown path instead of continuing to bootstrap.
- In dry-run mode, the script now skips the live API wait step so preview runs do not stall on an offline cluster.
- After bootstrap, Flux resources are resumed and reconciled.
- Keep this runbook aligned with `clusters/atlas/flux-system/gotk-sync.yaml`.