fix(tmux): keep browser keys from switching a tab onto another session (#669)

Squash of PR #669. Browser terminals could be moved onto another session
by tmux's prefix keys: Ctrl+B then ), (, s or w switched the tab's tmux
client to a different session while the tab kept the original's name.
Codeman's tmux socket now keeps only Ctrl+B Ctrl+B (send-prefix) in its
prefix table, and codeman tui and scripts/tmux-manager.sh get F1 as their
way out instead of Ctrl+B d.

Merge-time fixes by the maintainer: on an empty prefix table the
unbind-key that fails no longer skips binding send-prefix; a key tmux lists
escaped (prefix C-\ shows as C-\\) compares equal, so the reset does not rerun on every create;
and reconcileSessions() reduces the table at boot when the socket has live
sessions, so sessions that survive an upgrade are covered too.

Co-authored-by: christianhaberl <116439789+christianhaberl@users.noreply.github.com>
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

.changeset/tmux-prefix-table.md

@@ -0,0 +1,5 @@
+---
+"aicodeman": patch
+---
+
+Browser terminals can no longer be moved onto another session by tmux's prefix keys: typing Ctrl+B then `)`, `(`, `s` or `w` in a tab switched its tmux client to a different session while the tab kept the original's name. Codeman's tmux socket now keeps only Ctrl+B Ctrl+B (send-prefix) in its prefix table, so `Ctrl+B d` no longer detaches a terminal attached there: `codeman tui` and `scripts/tmux-manager.sh` detach with F1.