scripts: add 'o tui exit' to kill tmux session

data/scripts/o

@@ -263,6 +263,12 @@ cmd_tui() {
 
     local tmux_session="o-${s}"
 
+    # Subcommand: o tui exit
+    if [[ "${1:-}" == "exit" ]]; then
+        tmux kill-session -t "$tmux_session" 2>/dev/null && echo "[killed $tmux_session]" || echo "no tui session: $tmux_session"
+        return
+    fi
+
     # Kill existing tmux session if present
     tmux kill-session -t "$tmux_session" 2>/dev/null || true
 
@@ -306,6 +312,7 @@ commands:
   prompt            Interactive multi-line prompt REPL
   tail              Stream chat output
   tui               Launch tmux layout (chat + prompt + state + shell)
+  tui exit          Kill the tmux TUI session
   env [session] [agent]  Print session/agent env vars (eval-able)
   help              Show this help