Expose crash logs in TUI when Claude crashes #31
Description
Problem
When Claude crashes during a task, the TUI only shows:
```
🔄 Claude crashed, retrying (3/3)...
```
Even with `chief --verbose`, no additional debugging information is shown. The actual error is only available by manually inspecting `.chief/prds//claude.log`.
Example
A user running Chief in Docker saw only the retry message. The actual error (`--dangerously-skip-permissions cannot be used with root/sudo privileges`) was only discoverable by reading claude.log directly.
Suggested solution
- When Chief detects a crash, show the last few lines from the failed Claude process in the TUI
- At minimum, surface the stderr output from the crashed process
- Consider a "view crash log" shortcut key in the TUI