feat(PMEM-WP-0017): federated store management CLI and activity reports

Add phase_memory.management for cross-store discovery and windowed
activity reporting. Extend the phase-memory CLI with stores list and
report commands, plus make report-7d for the default weekly operator view.

docs/operator-readiness-runbook.md

@@ -55,6 +55,20 @@ Routes:
 - `POST /operations/{operation}`
 - `POST /operations` with `{"operation": "...", "payload": {...}}`
 
+## Cross-Store Activity
+
+Use the phase-memory CLI as the canonical cross-store activity check:
+
+```bash
+phase-memory stores list --format summary
+phase-memory report --days 7 --format summary
+make report-7d
+```
+
+Federated reports aggregate ops-warden coordination episodes and local graph
+store events/audit lines for the requested window. Drill into one store with
+`phase-memory report --store <store_id-or-path> --days N`.
+
 ## Readiness Checks
 
 Before accepting traffic: