docs: reshape runbooks into .agents/skills/<name>/SKILL.md (phase 4)

Problem: runbooks are agent-executable procedures but lived at the repo root,
separate from the other agent instruction now under .agents/.

Change:
- Move runbooks/<name>.md -> .agents/skills/<name>/SKILL.md (folder per skill,
  matching the wiki-hq skills layout). Frontmatter (name, risk_class, inputs,
  verification, docs_update_checklist, transition) preserved.
- Rewrite links (inbound from plans; between-skill siblings) via the move map.
- Update prose references in AGENTS.md, HERMES.md, .agents/OIKOS.md, and the
  operations schema; fix a pre-existing stale link to operations/commands.md.

No code consumed runbooks/ by path, so nothing else changes.

Verification: all SKILL.md frontmatter parses with valid risk_class; every
lifecycle transition resolves to an oikos/ontology.yaml state; broken-link
count 127 -> 126 (fixed one, introduced none).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

.agents/skills/lifecycle-activate-node/SKILL.md

@@ -0,0 +1,36 @@
+---
+name: lifecycle-activate-node
+risk_class: config_mutation
+inputs: [node_name]
+verification: "homelab service <name> health (if it hosts a service); homelab doctor (if it's a client)"
+docs_update_checklist: [doc_page_complete]
+transition: "provisioning -> active"
+---
+
+# Lifecycle: activate a node
+
+Per [oikos/ontology.yaml](../../../oikos/ontology.yaml). Requires: age key
+enrolled if it needs secrets, mesh joined if it needs off-LAN reach,
+ingress live if public, health check answering, doc page complete,
+ledger entry.
+
+1. If the node is a `homelab` client: finish enrollment per
+   [client-enrollment.md](../client-enrollment/SKILL.md) (`--finalize-pubkey`,
+   mesh join, `homelab doctor` green).
+2. If it hosts a public service: add the `services:` entry in
+   `inventory.yaml` (backend, url, doc_page, config_repo, risk_notes —
+   see the Week-1 service contract fields) and wire the Caddy route in
+   `dtoro/caddy-conf`.
+3. Confirm the health check answers: `homelab service <name> health` or
+   a direct `curl`.
+4. Flip `state: provisioning` → `state: active` (or delete the `state:`
+   field — `active` is the default) in `inventory.yaml`.
+5. Complete the doc page (stub → full narrative: role, specs, how it's
+   configured, dependencies).
+6. Record the activation: `oikos/ledger.py append host:<name> activate
+   config_mutation --result ok` (or let the CLI wrapper do this once
+   Week 3's runbook automation lands).
+
+Regenerate derived data: `python3 mcp/build_host_files.py && python3
+oikos/gen-topology.py` so `hosts/<name>.yaml`, the topology diagram, and
+the context card all reflect the new state.