BOXHEAD v0.2.1 HD — SHOP CURSOR RECAPTURE HOTFIX

- Preserves the v0.2.0 HD Complete combat, projectile, wave and infected gameplay core.
- Makes boxhead:ui_close a three-stage gameplay-return action:
    1. close_screen
    2. wait 1 client tick
    3. set_cursor_released=false
  The one-tick retry occurs after the DAI_DataScreen has actually left the GUI stack,
  allowing D.A.I.'s normal mouse-capture updater to grab the cursor again.
- All five Boxhead data screens now explicitly use close_on_escape=true and pause_game=false.
- No Java changes.
