Added event_bus.emit() calls for all 32 previously unwired EventType
members across domain services. Each emission includes contextual data
(plan_id, actor_name, tool_name, resource_id, etc.) for subscribers.
Events are fire-and-forget with error handling to prevent emission
failures from affecting service logic.
Services modified: plan_lifecycle_service, decision_service,
invariant services, actor runtime, tool execution, resource services,
sandbox/checkpoint, ACMS pipeline, validation runner, session service.
Added Behave tests verifying event emission for critical paths.
ISSUES CLOSED: #923
Luis Mendes