Oikos Week 2: Service Console v0, change ledger, node relations, runbooks

Adds the shared kernel modules (oikos/policy.py, oikos/relations.py,
oikos/ledger.py) that let every surface — CLI, MCP, context-card
generator — agree on risk classification and ontology graph walks
from one implementation.

homelab CLI: `service <name> explain|health|docs|log|actions|history`
(Service Console v0), `change preflight <service>`, `node <name>
relations`. Restart and client add/remove now append change-ledger
entries (ledger/*.jsonl, committed alongside the change they record).

mcp/server.py mirrors explain/preflight/get_relations/get_change_history
as MCP tools, card-first so agent orientation is one call instead of
several search_docs/get_page round-trips.

oikos/gen-topology.py now also emits a compact context card per host
and service (oikos/cards/*.md) — identity, blast radius, safe actions +
risk class, doc pointer, recent ledger history.

runbooks/*.md: service health check, config change + deploy, client
enrollment, incident investigation, and the five node lifecycle
transitions (provision/activate/migrate/deprecate/destroy), each with
machine-readable frontmatter (risk class, inputs, verification,
docs-update checklist). Wired into HERMES.md so agents load these
instead of rediscovering topology per-task.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

runbooks/lifecycle-migrate-node.md

@@ -0,0 +1,39 @@
+---
+name: lifecycle-migrate-node
+risk_class: config_mutation
+inputs: [node_name, source_host, target_host]
+verification: "homelab node <name> relations (re-check blast radius); homelab service <svc> health for every hosted service"
+docs_update_checklist: [doc_page_migration_note, inventory_host_and_lan_ip]
+transition: "active -> migrating -> active"
+---
+
+# Lifecycle: migrate a node
+
+Modeled on the strong Phase 1+2 migration
+([plans/2026-06-03_110000-library-ssd-migration-to-ludo-mini.md](../plans/2026-06-03_110000-library-ssd-migration-to-ludo-mini.md)).
+Requires (ontology): preflight + backup-verified before migrating;
+post-verify + Caddy backends checked + mounts checked + docs updated
+before returning to `active`.
+
+1. `homelab change preflight <every service the node hosts>` — capture
+   current health as a baseline.
+2. Verify backups are current for anything with data at rest on the
+   node (see `backs-up-to` edges once populated).
+3. Set `state: migrating` in `inventory.yaml`.
+4. Perform the migration (pct/qm move, or create-on-target +
+   data-copy + destroy-source, per the specific case).
+5. Update `inventory.yaml`: new `host:`, `lan_ip`, `mesh` addresses for
+   the node; update every `services:` entry whose `backend` pointed at
+   it if the backend name itself changes (usually it doesn't — only the
+   `host:`/`lan_ip` on the guest entry moves).
+6. Post-verify: re-run the Week-1 drift check by hand — confirm Caddy's
+   backend IP for each affected service matches the new `lan_ip`
+   (automatic in Week 3's drift detector), confirm mounts still resolve.
+7. `homelab service <name> health` for every service the node hosts.
+8. Set `state: active`. Add a migration note to the node's doc page
+   (old host/IP → new, date, phase reference) — this repo's convention
+   for every past migration (see `containers/101-jellyfin.md`,
+   `containers/129-house.md`).
+
+Regenerate: `python3 mcp/build_host_files.py && python3
+oikos/gen-topology.py`.