AgenticMail API/storage and outbound relay hardening fixes
The current upstream main branch at commit 7e0206d was reviewed, and the fix-first patch set was rebased on 2026-05-18. The patches cover: validated and bound inactive-agent hour filtering; storage SQL identifier validation; metadata-backed ownership checks for raw storage SQL; blocking direct storage metadata access through raw SQL; fail-closed outbound worker secret handling; SMTP envelope/header control-character validation before command construction; and TLS certificate verification as the default for MailSender with an …