V117 - In-game local account mailbox repair for Moonlight

What the uploaded runtime files proved
- The silent account service IS running on the BG2 host PC.
- The Drakhysys account already exists.
- The active UI.MENU supplied from the game still contained the older V113 string-mailbox writer instead of the V116 numeric writer.
- Baldur.lua contained no current Drakhysys Account request values, so the in-game UI was not delivering the live request the helper expected.
- A stale request from an older installation could remain after setup regenerated the channel, producing "This request belongs to another installation."

V117 changes
- Keeps the account screen inside BG2. No separate launcher window.
- Setup forcibly replaces any older DRAK account runtime block in the active override/UI.MENU.
- Setup verifies that the active UI.MENU contains the packed numeric mailbox before reporting success.
- Setup removes ONLY stale "Drakhysys Account" request entries from Baldur.lua before starting the new channel.
- Setup resets DRAKRSP.lua so an old response nonce cannot be mistaken for the new request.
- The helper ignores stale requests from a superseded installation instead of continuously reporting them as a service failure.
- CREATE ACCOUNT still only creates a local account that does not already exist.
- LOG IN is enabled only for an existing account.
- Each account keeps its own account.json, account.log and character files.
- No character backup, restoration, synchronization, automatic migration or deleted-character respawn is added.

Important character-folder rule
V117 does NOT automatically move existing loose files from the normal BG2 Documents/characters folder. If that folder contains old .CHR files, login can authenticate but account character routing remains locked until those loose files are moved manually to the account you choose or deleted by you. This is intentional to avoid hidden copies/backups/restores.

Setup
1. Close BG2.
2. Run SETUP_IN_GAME_ACCOUNTS.bat from V117.
3. Select the actual BG2 folder you launch and the Documents profile containing Baldur.lua.
4. Wait for the V117 installed confirmation.
5. Start BG2 normally or through Moonlight.
