- Merge branch event into session with before_branch/branch reasons
- Add before_switch, before_clear, shutdown reasons
- before_* events can be cancelled with { cancel: true }
- Update RPC commands to return cancelled status
- Add shutdown event on process exit
- New example hooks: confirm-destructive, dirty-repo-guard, auto-commit-on-exit
fixes#278
- Custom tools: TypeScript modules that extend pi with new tools
- Custom TUI rendering via renderCall/renderResult
- User interaction via pi.ui (select, confirm, input, notify)
- Session lifecycle via onSession callback for state reconstruction
- Examples: todo.ts, question.ts, hello.ts
- Hook examples: permission-gate, git-checkpoint, protected-paths
- Session lifecycle centralized in AgentSession
- Works across all modes (interactive, print, RPC)
- Unified session event for hooks (replaces session_start/session_switch)
- Box component added to pi-tui
- Examples bundled in npm and binary releases
Fixes#190
