Create payment portal link from posted subscription ID

When you post a subscription ID in channel it lacks a payment link, forcing billing staff to look it up manually. Get the portal link back in-channel so you can share it within minutes.

Overview

Dropping raw subscription IDs into a team channel should never force billing staff into manual lookups. This flow validates posted IDs, checks subscription status and returns a payment portal link in-thread so billing and customer success can share it with customers within minutes.