Add reply, reply-all, and forward endpoints with proper RFC 5322 threading
headers (In-Reply-To, References). SMTP send executes automatically when
approval threshold is met via nodemailer. Personal inbox CRUD lets users
connect their own IMAP accounts. Agent inbox system with regex-based rules
for auto-classify/auto-reply (drafts go through approval workflow).
Multi-sig email canvas shape (folk-multisig-email) with draft/pending/sent
states and 5s polling. Per-space auto-provisioning via onSpaceCreate.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Jeff Emmett