V406 RESUMED CAMPAIGN: EACH CONNECTED PLAYER REPLACES THEIR SAVED CHARACTER

- Keeps the original V405 archive unchanged.
- Only when loading a saved party (manual Load or automatic Resume), mark the
  session so each connected player's numeric Arbitration slot requires a new avatar.
- On host Arbitration, the native delete callback is tried only once for each
  joined player and account; it is NEVER run on a timer to restore characters.
- Once the slot is genuinely empty, the player may use native Import (account
  filename-filtered as in V401) or native Create. BG2 client-side empty slots
  can use Create even if the arbitration engine reports an in-game state.
- Native Play is blocked until connected players' replacement characters exist.
- No SAV, CHR, BIO, account profile, or character-folder files are deleted,
  moved, copied, or created by this UI-only patch.
- The existing V399 no-respawn logic and /characters/ folder remain unchanged.

QUICK UPDATE: Close BG2; run APPLY_V406_RESUME_PLAYER_SLOTS_UI_ONLY.bat
then choose the installation folder (containing BaldurII.exe). It patches only
BG2/override/UI.MENU, not the Documents profile. It does NOT rewrite existing
saved-game data. The full SETUP_IN_GAME_ACCOUNTS.bat is also included.

CAUTION: If BG2's native arbitration engine refuses deletion of the protagonist
or a currently controlled character, V406 leaves that character intact and
requires native/manual intervention; it never silently deletes saved-game files.
Windows multiplayer gameplay testing remains necessary.
