## Summary
C2 Mikado chain to move the entire Immich stack (server, ML, valkey,
postgres) off `minikube-indri` and onto `k3s-ringtail`. Immich is the
largest single tenant on minikube (~1.5 GiB resident) and minikube is
currently memory-saturated (97% RAM, swapping). This is the first
concrete chain in the broader indri-k8s decommission effort.
This PR contains the planning layer only — 7 cards (1 goal + 6
prerequisites). Implementation cycles follow per the Mikado Branch
Invariant.
## Goal end-state
- Immich `server`, `machine-learning`, `valkey` on ringtail.
- ML pod uses ringtail's RTX 4080 (performance win — currently
CPU-only).
- CNPG `immich-pg` (PG17 + VectorChord) runs on ringtail.
- Library still on sifaka NFS — ringtail mounts the same path.
- `photos.ops.eblu.me` reroutes through Caddy → ringtail ingress.
- Minikube `immich` and `immich-pg` are removed.
## Cards
| Card | Depends on |
|---|---|
| `migrate-immich-to-ringtail` (goal) | all six below |
| `cnpg-on-ringtail` | — |
| `immich-pg-on-ringtail` | cnpg-on-ringtail |
| `immich-pg-data-migration` | immich-pg-on-ringtail |
| `sifaka-nfs-from-ringtail` | — |
| `immich-app-on-ringtail` | immich-pg-on-ringtail, sifaka-nfs-from-ringtail |
| `immich-cutover-and-decommission` | immich-pg-data-migration, immich-app-on-ringtail |
## Key constraints
- **No data loss.** Downtime is acceptable; data loss is not. Two
surfaces matter: postgres (ML embeddings, face data — slow to
re-derive) and the library files (don't move, but NFS access from
ringtail must be verified).
- **Migration method:** Option A is a CNPG `externalCluster`
basebackup → promote. Option B is `pg_dump`/`pg_restore` as a
documented fallback. Either way, dry-run against a scratch
cluster first.
- **Why pg moves too** (not cross-cluster): keeping pg on minikube
would block the whole decommission, and Immich is chatty with pg
so tailnet round-trips would hurt.
## Test plan
- [ ] Plan review — does the dependency graph make sense?
- [ ] `mise run docs-mikado migrate-immich-to-ringtail` shows the
chain correctly.
- [ ] Per-card implementation cycles land separately (commit
convention enforced by hook).
Reviewed-on: #356
