Outreach Guardrails: Draft-First AI Replies

AI reply handling is now an explicit, owner-visible choice per lane — off, draft-first, or autonomous — and it defaults to drafting rather than sending. A hard fence keeps prospecting sequences away from addresses that already belong to a client.

• Off / draft-first / autonomous, chosen deliberately rather than inherited
• Existing-client addresses are blocked on the send path, not just hidden in the UI
• Disconnecting a mailbox removes the stored credential and revokes access at the provider