[Feature Request] Add COMBINED to MailRule.ConsumptionScope (body + attachments as one document)

Description MailRule.consumption_scope has three values: - ATTACHMENTS_ONLY -- each attachment becomes a document, body dropped - EMAIL_ONLY -- body becomes one document, attachments dropped - EVERYTHING -- body + each attachment as N+1 separate documents No way to get a single combined document per email. Receipt/transactional intake hits this fast: some receipts come as PDF attachments, others as the HTML body, and EVERYTHING produces unwanted duplicates (1 body doc + 1 attachment doc per email-with-attachment). Proposal: add COMBINED (= 4 or similar), label "Process the email as one combined document". When set, MailHandler skips the separate attachment-queue dispatch and the parser embeds attachments into the produced PDF. Parser-side mechanics are already proven -- I shipped a plugin ( that does body + attachment embed via pypdf. Upstream's MailDocumentParser would do the same via Gotenberg's merge route (…