docs: factory integration grill — decision record, ADRs, and chunk scope update

- Decision record covering 12 decisions from the factory integration grill
- ADR-0008 (factory boundary: this repo is a provider, not a factory instance)
- ADR-0009 (flat skill taxonomy with category metadata in frontmatter)
- ADR-0010 (role skills in .agents/skills/; core/agents/ for subagent definitions)
- Issue 0013 (LESSONS.md at repo root)
- Issue 0014 (docs/spec/ living spec layer + VISION.md refactor)
- ROADMAP Chunk 3 scope expanded: skills rebuild, new skills (session-handoff,
  governance-check, git-guardrails, write-adr), IaC/Gitea global optional
- Per-skill process: implementation guidance Sections 4-5 and skills index
  referenced as starting point before web research and grilling
- factory-research-gaps-conflicts.md marked superseded

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

docs/issues/0013-lessons-md.md

@@ -0,0 +1,32 @@
+# 0013 — LESSONS.md for this repo
+
+## What to build
+
+Create `LESSONS.md` at the repo root. This file is the long-loop feedback mechanism for this repo — patterns noticed during active development get written here, and repeated patterns graduate to standing rules.
+
+**File structure:**
+
+```markdown
+# Lessons
+
+Patterns observed during development of this repo. Three or more entries on the same pattern → promote to CONTEXT.md (or the relevant instruction file) as a standing rule.
+
+## [date] [short title]
+[observation — what happened, what was learned, what should change]
+```
+
+**Graduation rule:** When three or more entries cover the same pattern, the human reviews and promotes the pattern to the appropriate standing location: CONTEXT.md for domain-level principles, `core/instructions/coding.md` for coding conventions, `core/instructions/git.md` for git conventions, or `core/instructions/testing.md` for testing conventions. The graduated entries are marked `[graduated → target file]` rather than deleted (audit trail).
+
+**Who writes to it:** The session-handoff skill (Chunk 3) prompts LESSONS.md extraction before closing a session. The human may also write directly.
+
+**What belongs here:** Non-obvious observations — a rule that was misapplied, a pattern that caused friction, a decision that turned out wrong in practice. Not summaries of what was built (that's git history) or planned changes (that's issues).
+
+## Acceptance criteria
+
+- [ ] `LESSONS.md` exists at repo root with the structure above
+- [ ] Graduation rule is documented in the file header
+- [ ] CONTEXT.md docs convention is updated to reference LESSONS.md as an artifact type
+
+## Blocked by
+
+None.