Add operational runbooks and decisions stub

docs/00-governance/CLEANUP_LOG.md

@@ -20,3 +20,4 @@
   - `docs/archive/phase-history/PHASE2_COMPLETION_REPORT.md`
 - Added a softer revision note to `README.md` instead of a historical warning.
 - Marked `docs/INDEX.md` historical in place because it currently misdirects navigation.
+- Added follow-up debt: shared metrics vocabulary currently duplicated in `docs/02-runbooks/backtest_review_workflow.md` and `docs/02-runbooks/live_test_review_workflow.md`; later extract to shared governance doc `docs/00-governance/metrics_vocabulary.md`.

docs/00-governance/decisions.md

@@ -0,0 +1,15 @@
+# Architecture Decisions
+
+Use this file to record durable project decisions that affect implementation patterns, interfaces, or workflow.
+
+## Decision Template
+- ID: DEC-YYYYMMDD-XX
+- Date:
+- Status: proposed | accepted | superseded
+- Context:
+- Decision:
+- Consequences:
+- Related Files:
+
+## Decision Log
+- No decisions recorded yet.