/api/checkout now resolves the requested plan (pro|business × monthly|annual)
to a plan GUID via gateway /v1/plans (codes follow pro_monthly / business_annual)
and POSTs /v1/users/me/plan/purchase. The payments service owns the gateway
(ZarinPal/Stripe) and returns redirect_url, which we hand back unchanged.
Removes the orphaned Stripe→Supabase webhook + lib/stripe.ts client: profile
plan reads come from Identity now, so the Supabase profiles upsert loop is dead.
V2 payments has its own gateway callback (skip-auth, payment-callback route).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
soroush.asadi
9555044485