Gmail Gatekeeper: let createDraft() set From to a verified send-as alias

[schainks]

Gmail accounts often send as several addresses (Settings → Accounts → “Send mail as”). GmailDraftInput has no from field, and buildSendRaw writes from: this.selfEmail, so every draft carries the account’s primary address. I run several businesses from one Workspace mailbox, so I change From by hand on every agent-written draft before sending. If I forget, the mail goes out under the wrong business 😢

Proposal: an optional from on GmailDraftInput and GmailDraftPatch. The Gatekeeper accepts it only if it matches a verified entry from users.settings.sendAs.list, and refuses it otherwise. The draft’s approval description shows the chosen From. Label and search bindings keep refusing to compose.

I can test a branch against a Workspace account with aliases if that helps y'all.