Wired up Polar.sh for subscriptions, with tiers from hobby up to enterprise and a 10% grace period that bills per head once you go over. New Prisma models for subscriptions, usage records, and add-on purchases, a webhook route, and a full billing settings page with usage meter, history, and upgrade flow. Also had to revert the Next.js 16 upgrade from earlier in the day, since cacheComponents and friends were not playing nicely, so we are back on 15.5.9. Tail end of the day was small webhook and UI fixes, including hiding the billing portal link from people who aren't actually paying for anything.

6 commits across 1 repo (heeler: 6). 41 files changed; 1 skipped. Diff was truncated for summarization.