A1: migration 021 — partner attribution (pre-apply commit, per docs/PARTNERS.md)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

supabase/migrations/021_partner_ref.sql

@@ -0,0 +1,46 @@
+-- ---------------------------------------------------------------
+-- 021 — partner attribution (A1 Session 3, per docs/PARTNERS.md).
+--
+-- Adds user_profiles.partner_ref (the external partner code captured from
+-- the ?ref= cookie at signup and stored in auth metadata), extends
+-- handle_new_user to copy it on profile creation (verified against the
+-- LIVE function definition — it inserts (id, email) only; this adds one
+-- column and preserves SECURITY DEFINER + search_path), and backfills
+-- rows whose auth metadata already carries a ref.
+--
+-- Distinct from migration 004's USER-referral system: partner codes are
+-- external strings; no dependency on referral_codes tables.
+-- ---------------------------------------------------------------
+
+ALTER TABLE public.user_profiles
+  ADD COLUMN IF NOT EXISTS partner_ref text;
+
+CREATE INDEX IF NOT EXISTS idx_user_profiles_partner_ref
+  ON public.user_profiles(partner_ref)
+  WHERE partner_ref IS NOT NULL;
+
+CREATE OR REPLACE FUNCTION public.handle_new_user()
+RETURNS trigger
+LANGUAGE plpgsql
+SECURITY DEFINER
+SET search_path TO 'public'
+AS $function$
+begin
+  insert into public.user_profiles (id, email, partner_ref)
+  values (
+    new.id,
+    new.email,
+    upper(nullif(new.raw_user_meta_data->>'partner_ref', ''))
+  )
+  on conflict (id) do nothing;
+  return new;
+end;
+$function$;
+
+-- One-time backfill for signups that predate the column.
+UPDATE public.user_profiles p
+SET partner_ref = upper(u.raw_user_meta_data->>'partner_ref')
+FROM auth.users u
+WHERE u.id = p.id
+  AND p.partner_ref IS NULL
+  AND nullif(u.raw_user_meta_data->>'partner_ref', '') IS NOT NULL;