V319 - CHR UNREADABLE BY DEFAULT / THREE ACCOUNT LETTERS
Base: V318. Account, multiplayer, save, death, arbitration and character content unchanged.

PRIMARY RULE (Import, and native character file presentation):
  No authenticated active account => no CHR rows to import.
  Active account Drakhysys  => only dra01.CHR, dra02.CHR, etc.
  Active account Kronas     => only kro01.CHR, kro02.CHR, etc.
  Files whose FIRST THREE LETTERS do not match the current account are not
  mounted in the engine's root Import view and never appear in Import.
  The native engine list is treated as UNTRUSTED. On Done, the selected row is
  rechecked against the active account's verified folder and mounted aliases.
  The source CHR must also begin with the account's three-letter prefix, e.g.
  Drakhy.CHR for Drakhysys or Krokro.CHR for Kronas.
  Only a logged-in, activated account has a readable alias snapshot.

EXPORT:
  BG2's existing Export actions stay normal. New exports are assigned the next
  account-specific numbered filename (dra01.CHR, kro01.CHR, etc.) and copied to
  characters/<AccountName>/ by the V318 copy bridge.
  Any mismatching original .CHR remains untouched in the account folder; it is
  simply hidden from Import unless renamed to the correct prefix by the owner.

The three-letter prefix is intentionally retained for this trial. Accounts
with the same first three letters are NOT uniquely identified by filename alone;
account validation and physical account folder checks are necessary too. A
possible five-letter prefix can be considered after live BG2 tests.

INSTALLATION: Exit all BG2 sessions, run SETUP_IN_GAME_ACCOUNTS.bat, point to
BaldurII.exe game folder and the BG2 profile containing Baldur.lua. Run
InfinityLoader.exe with EEex. No existing account folders/CHR files are deleted
or renamed by this change. Keep V318 available for rollback if needed.

NOTE: Static and simulated-router tests cannot guarantee engine behavior;
verify Import and Export after login to Drakhysys and Kronas separately.
