feat(ai-vterm): surface surviving tmux sessions in the project picker

Each project's tmux session is now named `<cj/ai-vterm-tmux-session-prefix><basename>` (default `aiv-`), so `tmux ls` can be filtered to AI-vterm's own sessions. After an Emacs crash the C-F9 project picker reads `tmux list-sessions`, matches surviving sessions back to their directories, and sorts those to the top: `[detached]` when only the tmux session is alive, `[running]` when a vterm buffer exists. The rest follow alphabetically. With tmux missing or no server running, it falls back to a plain alphabetical list. The picker's collection is a completion table that pins display order so Vertico doesn't re-sort and undo the active-first grouping.

The prefix is a new `defcustom` rather than `claude-`, which collides with hand-rolled tmux sessions. Sessions named before this change use the bare basename and won't be matched afterward. One `tmux kill-server` clears any orphans.

0 files changed, 0 insertions, 0 deletions