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.md

@@ -76,7 +76,8 @@ Grep is fine for browsing or when MCP is unreachable.
 ## 4. Wiki conventions
 
 - Narrative pages live under `knowledge/wiki/{containers,hosts,vms,infrastructure}/`;
-  procedural pages under `investigations/`, `operations/`, `runbooks/`, `plans/`.
+  runbook procedures under `.agents/skills/<name>/SKILL.md`; other procedural
+  pages under `investigations/`, `operations/`, `plans/`.
   Cross-link liberally; orphans are bugs.
 - Every page ends with a `## Changelog` section, entries in reverse-chrono
   order: