draftEmail creates a message in Gmail without sending it. Use it for approval
flows, human review, or messages that will be completed in Gmail later.
Example
automations/draft-follow-up.automation.ts
Inputs
Recipient is an email string or { address: string; name?: string }.
Attachment is a File or an object containing file with optional
filename, contentId, and disposition: "attachment" | "inline".
Every input, including account, also accepts a compatible Signal.
Output
Returns aSignal<DraftIdentifier> with:
draftId and messageId are different identifiers. Pass draftId to
getDraft, updateDraft, sendDraft, or deleteDraft.