refactor: self-compliance run — write-skill against its own standard

- Insert explicit self-check step (step 9) before HITL (step 10);
  self-check runs after write-eval so all items are verifiable
- Remove HITL from self-check checklist — HITL may occur across a
  PR boundary after the session ends
- Fix frontmatter constraint and self-check item to acknowledge
  optional `model:` field alongside `allowed-tools`
- Conflict-check sub-agent now also reads factory-integration-decisions.md
  with explicit precedence rule: integration decisions override factory
  principles — prevents false positives from deliberately overridden decisions
- Bump to v1.5

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.agents/skills/write-skill/META.md

@@ -1,5 +1,5 @@
 ```yaml
-version: "1.4"
+version: "1.5"
 updated: 2026-05-26
 
 # when: describes when this skill is loaded — the full trigger context.