Slack Interactions

Verify + ACK (<3s); enqueue an approval resume for button clicks.

Four answer shapes, because Slack reads them differently. A block_actions click is happy with any 2xx and keeps the {"ok": true} body it has always had. A view_submission is not: Slack closes the modal only on a 200 with an EMPTY body, and treats a JSON body as a response_action instruction, and {"ok": true} names none, so the modal would sit there looking broken. A submission the service could not carry out answers with a real response_action — without one the modal closes as though it had worked. And a block_suggestion type-ahead request wants neither: it must get its {"options": [...]} body back, on every keystroke, or the field simply shows nothing.

The service decides all four and this route only relays them, INCLUDING the body: composing a response_action or an options list here would put user-facing copy in a transport.

allow-long-function: one four-way relay over the answer shapes documented above; splitting it would separate a branch from the Slack behavior it exists to match.