The SHA-256 integrity check introduced in migration 0007 blocks saves
when a character's savedata blob is imported from another server instance,
because the stored hash in the target DB no longer matches the new blob.
Adding DisableSaveIntegrityCheck (default: false) lets server operators
bypass the check to unblock cross-server save transfers. A warning is
logged each time the check is skipped so the flag's use is auditable.
Documents the per-character SQL alternative in CHANGELOG:
UPDATE characters SET savedata_hash = NULL WHERE id = <id>
Closes#183.
0ea399f135