V253 - PLAY ENTERS THE GAME; ARBITRATION EVENTS ARE CONSUMED ONCE

INSTALL
1. Close every BG2 window so the old Lua hooks are unloaded.
2. Extract this package and run SETUP_IN_GAME_ACCOUNTS.bat.
3. Choose the BG2 game folder and its Documents/profile folder, then restart BG2.

CHANGES
- Opening Arbitration consumes the pending join/leave event. An event received
  while that screen is already open does not request another visit.
- Play consumes pending Arbitration before cleanup or the native Done callback.
  The native Play/Done callback runs once; reentrant redraws cannot reopen the
  same event or call Play again.
- Repaired an older player-update wrapper accidentally left outside the embedded
  account script. In V252 it could recursively call itself instead of updating
  the native player row. The installer repairs that function in existing UIs too.
- Temporary player-row clears/refills during Play are compared as a completed
  roster. They do not immediately delete a connected player's character. A
  lasting join/leave during that transition is handled after the refresh window.
- Later remote-player joins and leaves still request one Arbitration visit.
- The clock-unavailable fallback now releases the Play guard instead of leaving
  it permanently active. A failed/cancelled Play also releases the guard.
- Native account Import/Export remains available with the V252 folder router.
  No automatic character copies, backups, restoration, or respawning were added.

VALIDATION
- Reproduced the supplied V252 recursive-hook failure with executed Lua.
- 33 unit/Lua tests and 6 account Import/Export regression checks pass in the
  development environment. Tests execute both the native UI updater and the
  embedded account runtime, including Play, redraws, joins, leaves and kicks.
- An installer smoke test upgrades the supplied V252 UI in a temporary profile.
- Run RUN_IN_GAME_ACCOUNT_TESTS.bat for the current checks. Lua execution requires
  an available Lua 5.2/5.3/5.4 library; those checks are reported as skipped if absent.
- A live Windows BG2 multiplayer session has not been run here. In-game check:
  press Play, wait in the world, join a second player, press Play again, then
  disconnect that player. Each new connection change should open Arbitration
  once; pressing Play with the same roster should return to the game and stay there.
