docs(structure): govern .planning/ and register the ops runbook

- docs/STRUCTURE.md: add a .planning/ registry (vision/roadmap/history/breakdown
  roles), broaden the roadmap role, add enforcement items 8-10.
- tools/check_requirements.py: scan .planning/ too - every .planning/**.md must be
  registered, registered files must exist, requirement rows rejected there.
- .planning/: PROJECT.md, ROADMAP.md, MILESTONES.md, and milestones/v0.5/M3/
  {roadmap.md,task_breakdown.md}. M3 breakdown holds only the tasks; decisions live
  in the contracts.
- docs/DEPLOYMENT.md: add the ops runbook (registered as ops).

.planning/milestones/v0.5/M3/roadmap.md

@@ -0,0 +1,30 @@
+# M3 — roadmap
+
+Role: roadmap. Objectives for v0.5 / M3. Cites requirement IDs; defines none.
+
+## Objective
+
+A Photos-ready slab becomes submission-ready for WooCommerce, and a practice `SLAB-UAT-*` draft
+matching the reviewed ready set exists in the store. Create works with inference off.
+
+## Capabilities in scope
+
+- Woo connection (WordPress application password) and taxonomy sync.
+- Review to the full ready set, with per-slab pricing and override.
+- Inference assist (Call 1 / Call 2), optional and never blocking create.
+- Publish: create the Woo product; `SLAB-UAT-*` always a draft.
+
+## Sources of truth
+
+- Behavior and acceptance: `docs/capabilities/CREATE.md`.
+- Scope and the M3 ID subset: `docs/MILESTONES.md`.
+- Interfaces: `docs/contracts/` (`API.md`, `WOO-API.md`, `DATA-MODEL.md`, `PROMPTS.md`, `UX.md`,
+  `CONTENT-WOO.md`, `TEST-SPEC.md`).
+
+## Exit
+
+Per `docs/MILESTONES.md` and `docs/capabilities/CREATE.md` (QUALITY-110).
+
+## Note
+
+M3 implementation has not started. Decisions already ruled live in the contracts, not here.