Salvage previously dropped worm_audit_records and filter_execution_logs
entirely, losing tamper-evident audit/ledger history on recovery, and
hardcoded every salvaged account's imap_tls_mode/smtp_tls_mode back to
ImplicitTls regardless of the account's real configured mode. Salvage
now carries both ledger tables through recovery verbatim, including
their hash-chain columns, and reads each account's real TLS modes from
the salvaged row, WARN-logging and falling back only when a raw value
is genuinely unrecognized.
Refs #248