Add three new pages completing the control-room web UI:
- Agent activity: polls /agent-activity every 5s, filterable by type/agent
- Knowledge search: FTS over /knowledge/search with snippet + entity links
- Audit trail: browseable audit log with actor/action/entity filters
Enhanced live events page with correlation-id clustering (Groups toggle).
Added fetchAgentActivity/searchKnowledge/fetchAudit to the API client.
11 nav items now cover all planned control-room views.