feat: real-time agent observability panel (Phase 1)

[DorianZheng]

Summary

• add real-time agent activity plumbing in Dune main process: runtime action, IPC bridge, fs.watch()-based status watcher, and renderer updates
• add a collapsible AgentActivityPanel to the app sidebar so live agent tool activity is visible without polling
• instrument AgentLite action execution to write {dataDir}/ipc/status.json before/after tool calls and on terminal done/error transitions
• refresh the pinned @boxlite-ai/agentlite dependency to the AgentLite observability commit that now builds correctly from a fresh GitHub install

Validation

• ./node_modules/.bin/tsc --noEmit
• pnpm test
  • still fails with the same 7 baseline failures present on the original repo before this work:
    • src/renderer/app/AppShell.test.tsx (4 failures)
    • src/renderer/app/store/runtime-sync.test.ts
    • src/renderer/features/agents/runtime/agent-runtime.test.ts
    • src/renderer/features/settings/config/settings-sections.test.ts
• AgentLite: pnpm run build
• AgentLite: pnpm exec vitest run src/agent/status-writer.test.ts src/agent/actions-http.test.ts
• clean temp install of @boxlite-ai/agentlite@github:boxlite-ai/agentlite#54e4a4edf8e852fa96d72736ca834fed15616be7 verified the generated dist/agent output contains the new observability code

Notes

• Dune now points at AgentLite commit 54e4a4edf8e852fa96d72736ca834fed15616be7 for the status-file instrumentation used by this panel.
• Companion AgentLite PR: feat: add agent activity status files boxlite-ai/agentlite#64