V204 focused checks

PASS - account folder identity flag is created with matching account/flag name.
PASS - activating Drakhysys does not deactivate Kaos, and vice versa.
PASS - named logout deactivates only the named account flag.
PASS - mismatched characters_<accountname> identity flag is rejected.
PASS - missing account folder is not recreated by login/activation validation.
PASS - logout clears the shared selector only when that logged-out account owns it.
PASS - Lua login checks only the requested '<ACCOUNTNAME> Activate' flag.
PASS - Lua login sets only that requested flag to 1.
PASS - Lua logout waits for router confirmation and then sets the same account flag to 0.
PASS - installer/UI patch embeds the V204 runtime and keeps Delete Account disabled.
