0.6.1 — keepalive(), so a free Supabase project never pauses

A new migration (20260910170000_keepalive.sql) adds public.keepalive(): STABLE, no arguments, reads no table, returns now(), EXECUTE granted to anon. Anything that pings on a schedule — Mosayic's keep-alive, a GitHub Actions cron, an uptime monitor — can call GET https://<ref>.supabase.co/rest/v1/rpc/keepalive with just the publishable key in the apikey header, and Supabase's inactivity clock resets. Like delete_own_account(), it exists in production the moment your first release runs the migrations — no API deploy needed. Package version stays 0.0.1 by design.