fix(hook): use tee-based capture instead of PTY proxy

[moukrea]

Summary

The previous fix (#13) tried to fix hook-induced terminal issues by tweaking the PTY proxy — that approach was wrong and broke colors. This PR takes the correct approach: eliminate the PTY proxy entirely for hooked sessions.

The hook (eval "$(snag hook bash)") was using exec snag wrap to interpose a PTY proxy between the terminal and the shell. This broke the terminal's direct relationship with the shell process, causing:

• Tab titles stuck at ~:bash (terminal couldn't track the shell's title/CWD)
• New tabs always opening in ~ (terminal couldn't read the shell's CWD via procfs or OSC 7)
• Colors broken (from the login shell regression in fix(hook): restore terminal title updates and new-tab CWD inheritance #13)

The fix: replace exec snag wrap --capture <path> with exec > >(tee -a <path>) 2>&1 — the same tee-based capture mechanism that adopted sessions already use. This keeps the shell as the terminal's direct child process, preserving all terminal integration (titles, CWD tracking, colors, VTE hooks).

Also reverts all cmd_wrap changes from #13 (login shell, SHLVL, OSC 7 parsing, removed title) to restore its original behavior for direct usage.