WP-0016 finished: interactive registry maintain with llm-connect automation

Closes the registry maintenance loop from inside each domain repo:
interactive prompting for judgment calls, full automation for safe and
high-confidence changes, both backed by the llm-connect HTTP bridge.

- New modules: maintain.py, maintain_llm.py, patches.py, interactive.py
- Schema: schemas/registry-patch.schema.json
- CLI: reuse-surface maintain; establish --scaffold --hook
- Sibling templates: Makefile fragment, pre-commit hook
- Deterministic signal collectors extended; validate cwd auto-detect
- Docs, gap priority 28, SCOPE update
- Tests: test_maintain.py, test_interactive.py (59 pytest total)

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

registry/README.md

@@ -50,6 +50,33 @@ Discover drafts start at low maturity with explicit auto-draft risks in
 `known_reliability_risks`. Promote only with evidence per
 `specs/CapabilityMaturityStandard.md`.
 
+## Maintain session checklist (REUSE-WP-0016)
+
+After code or doc changes in the owning repo:
+
+```bash
+reuse-surface maintain --all --from-git-since origin/main
+reuse-surface validate
+git add registry/ && git commit -m "registry: maintain session"
+git push origin main
+```
+
+Automation (CI or pre-commit):
+
+```bash
+reuse-surface maintain --all --auto --no-llm
+```
+
+With llm-connect for maturity suggestions:
+
+```bash
+export LLM_CONNECT_URL=http://127.0.0.1:8088
+reuse-surface maintain --all --from-git-since HEAD~5
+```
+
+Review every non-deterministic patch before merge; promotions require evidence
+citations on disk per `specs/CapabilityMaturityStandard.md`.
+
 ## Manual validation checklist
 
 Use this checklist until an automated CLI validator exists.