Writing Supabase Edge Functions

Description

Build, advise on, and review Supabase Edge Functions — Deno runtime and imports (npm and jsr specifiers, per-function deno.json), Deno.serve handlers, JWT verification (platform verify_jwt vs verifying claims in code), creating Supabase clients with the caller's token so RLS applies, secrets management, CORS and preflight, webhooks with signature verification and no-JWT mode, background work (EdgeRuntime.waitUntil), timeouts and resource limits, local serve/test, deploy, logging, and keeping Deno code separate from the Node app's tooling. Use whenever supabase/functions exists, the user writes or debugs an Edge Function, receives a webhook in Supabase, sees CORS or 401 errors calling a function, or deploys functions.