Captures the post-mortem of the April 13 power-cut: incident timeline,
retrospective, and architecture/role diagrams. Adds an ADR explaining why
Longhorn cannot re-associate orphaned replica directories after a nuclear
reinstall (engine-id naming), plus block-device recovery runbooks and the
`playbooks/recover/longhorn_data.yml` automation that wires `merge-longhorn-layers.py`
to rebuild PVCs from raw `volume-head-*.img` chains.
Also extends the k3s_pvc backup to capture Longhorn `volumes`/`settings` CRDs
(needed for the fast-path restore) and rewrites the restore script with a
fallback dir + English messages.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Gabriel Radureau
1ae28cb944