When IMAP_EMAIL_SEED / POP3_EMAIL_SEED points at a directory of .eml
files (the orchestrator emailgen worker's drop path,
/var/spool/decnet-emails/ by convention), the bait mailbox is replaced
with those LLM-generated, persona-driven, threaded messages. Empty /
missing dir keeps the hardcoded fallback so a fresh deployment is never
silent. Cached with mtime invalidation + a short TTL so a hot mailbox
doesn't pay the parse cost on every IMAP/POP3 command.
Replaces the DEBT-026 stub on both templates that named the env var but
never wired it through.