Session list: include TTY and tmux pane metadata

[benvinegar]

Problem

When multiple Hunk sessions are running, it's hard to tell which session corresponds to which terminal window. The only identifying info is repo path and title, which can be identical across sessions.

Suggestion

Add optional tty and tmuxPane fields to HunkSessionRegistration so hunk session list (and the daemon API) can surface which terminal a session belongs to.

Available at registration time:

• TTY path: readable via ttyname() or /proc/self/fd/0 readlink
• TMUX_PANE: env var set by tmux (e.g. %3)
• TMUX: env var with the tmux socket path

Example output:

5539f294  hunk show HEAD  [tmux %3]
  repo: /Users/benvinegar/Projects/hunk

This came up during a real debugging session where a stale process kept a ghost session registered, and it was unclear which session was the live visible one.

[benvinegar]

Maybe Ghostty too?