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.

tests/fixtures/management/local-store/audit.jsonl

@@ -0,0 +1,2 @@
+{"operation":"package.compile","operation_id":"op:audit-old","timestamp":"2026-06-02T08:00:00+00:00"}
+{"operation":"audit.query","operation_id":"op:audit-in-window","timestamp":"2026-07-02T10:00:00+00:00"}