### Breaking
- **Session hooks API redesign**: Merged `branch` event into `session` event. `BranchEvent`, `BranchEventResult` types and `pi.on("branch", ...)` removed. Use `pi.on("session", ...)` with `reason: "before_branch" | "branch"` instead. `AgentSession.branch()` returns `{ cancelled }` instead of `{ skipped }`. `AgentSession.reset()` and `switchSession()` now return `boolean` (false if cancelled by hook). RPC commands `reset`, `switch_session`, and `branch` now include `cancelled` in response data. ([#278](https://github.com/badlogic/pi-mono/issues/278))
### Added
- **Session lifecycle hooks**: Added `before_*` variants (`before_switch`, `before_clear`, `before_branch`) that fire before actions and can be cancelled with `{ cancel: true }`. Added `shutdown` reason for graceful exit handling. ([#278](https://github.com/badlogic/pi-mono/issues/278))
### Fixed
- **File tab completion display**: File paths no longer get cut off early. Folders now show trailing `/` and removed redundant "directory"/"file" labels to maximize horizontal space. ([#280](https://github.com/badlogic/pi-mono/issues/280))
- **Bash tool visual line truncation**: Fixed bash tool output in collapsed mode to use visual line counting (accounting for line wrapping) instead of logical line counting. Now consistent with bash-execution.ts behavior. Extracted shared `truncateToVisualLines` utility. ([#275](https://github.com/badlogic/pi-mono/issues/275))