Use PA-specific tmux config for power mode theme

Both pa-mode and pa-launch now use ~/.tmux-pa.conf which applies
a Dracula purple theme to visually distinguish privileged sessions.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

automation/pa-mode

@@ -48,7 +48,8 @@ create_or_attach_session() {
 
     # Using -A: attach if session exists, create if not
     # exec replaces this shell with tmux
-    exec tmux new-session -A -s "$SESSION_NAME" -c "$HOME" \
+    # Uses PA-specific config for distinct "power mode" visual theme
+    exec tmux -f ~/.tmux-pa.conf new-session -A -s "$SESSION_NAME" -c "$HOME" \
         "$CLAUDE" --dangerously-skip-permissions --agent personal-assistant
 }