feat: detect orphaned sessions (terminal closed but Claude process alive)

[grimmerk]

Problem

A session can be active (PID alive) and idle (hook status), but its parent terminal has been closed. CodeV shows it as green (idle), which is misleading — the user can't interact with it without reattaching.

How claude-control does it

Uses isOrphaned() — walks process tree (via ps -e) looking for known terminal apps (iTerm2, Terminal.app, Ghostty, etc.). If not found → ORPHANED. Checks every 30s. Uses ps process tree, not ~/.claude/sessions/*.json.

How CodeV can implement it

We already have the infra:

1. detectTerminalApp(pid) walks the process tree and returns 'iterm2', 'ghostty', 'cmux', 'terminal', or 'unknown'
2. Active sessions detected via ~/.claude/sessions/*.json (PR feat: rewrite detection with sessions/ PID files + cross-ref fallback #67)

Detection logic:

• For each active session (PID alive from sessions/*.json):
  • Skip non-CLI sessions (entrypoint !== 'cli')
  • Call detectTerminalApp(pid)
  • If returns 'unknown' → session is orphaned

When to check:

• On get-session-statuses call (startup + window focus)
• Can reuse the detectTerminalApp calls already done for terminal badges

UI:

• New dot state: grey or dimmed purple (static) with ORPHANED implied
• Or show as a badge like claude-control does
• Possible actions: kill orphaned process

Edge cases:

• VS Code sessions (entrypoint: 'claude-vscode') — not orphaned even if no terminal found
• SSH/remote sessions — process tree may not have a local terminal app

🤖 On behalf of @grimmerk — generated with Claude Code