Add ACMCC app source, Supabase backend, and project config

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

supabase/migrations/20260508022917_d947fac0-5615-4cf7-ba5e-b080424bbe22.sql

@@ -0,0 +1,10 @@
+CREATE POLICY "Users can delete own messages"
+ON public.direct_messages
+FOR DELETE
+TO authenticated
+USING (
+  auth.uid() = sender_id
+  OR auth.uid() = recipient_id
+  OR public.has_role(auth.uid(), 'admin'::public.app_role)
+  OR public.has_role(auth.uid(), 'manager'::public.app_role)
+);