feat: centralized PTY-scoped session state, sync engine debug panel, lifecycle states, WS monitor

- Refactor session state to use ptySessionId as primary key across all components
- Add SessionStateManager with PTY-scoped hook processing, approval tracking, notifications
- Add sync-engine debug panel (AgentStatesSection, HookTimelineSection, TerminalRegistrySection, WsMonitorSection)
- Add useLifecycleStates composable for continuous state chips (session, responding, tool, subagent, compacting)
- Add WS monitor endpoint and composable for real-time connection health
- Enhance SessionLifecycleStatus with animated state chips and badge counts
- Enhance SystemMessage with expanded content and better formatting
- Update hooks (approval-permission, approval-plan, notify) with pty_session injection
- Update approval system to derive pending lists from PTY-scoped state
- Update ChatContainer with PTY-derived agent status and lifecycle events
- Update AgentBadge with PTY-scoped status colors
- Improve PiP window, approval window, and loading window handling

frontend/src/components/transcript-debug/index.ts

@@ -18,3 +18,4 @@ export { default as ResumeTerminalButton } from './ResumeTerminalButton.vue'
 export { default as VoiceMicButton } from './VoiceMicButton.vue'
 export { default as NewSessionModal } from './NewSessionModal.vue'
 export { AquaticBackground } from './aquaticBackground'
+export { SyncEnginePanel } from './sync-engine'