revert(hypr): remove game-focus-watcher, restore steam rules

Keep only DP-1 forcing changes: gamingMonitor variable, monitor rules
for steam_app/mkGameRules, gaming-focus script, and SUPER+G binding.

Remove game-focus-watcher (caused game freeze on workspace switch).
Revert steam workspace rule back to title:Steam only.
Revert ghostty exec-once order.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/ghostty/default.nix

@@ -74,7 +74,7 @@
   ];
 
   wayland.windowManager.hyprland.settings.exec-once = [
-    "[workspace 1] uwsm app -- ghostty -e bash -c 'fastfetch; exec $SHELL'" # TODO: must be xdg-terminal-exec, or default user terminal
     "[workspace special:preload silent] uwsm app -- xdg-terminal-exec"
+    "[workspace 1] uwsm app -- ghostty -e bash -c 'fastfetch; exec $SHELL'" # TODO: must be xdg-terminal-exec, or default user terminal
   ];
 }