Add ACMCC app source, Supabase backend, and project config

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

supabase/migrations/20260411181409_45b66876-3e7f-4403-8df4-e3aefc5b8c7f.sql

@@ -0,0 +1,9 @@
+
+DROP POLICY IF EXISTS "Users can view own association billable expenses" ON public.billable_expenses;
+
+CREATE POLICY "Staff can view billable expenses"
+  ON public.billable_expenses FOR SELECT TO authenticated
+  USING (
+    has_role(auth.uid(), 'admin'::app_role)
+    OR has_role(auth.uid(), 'manager'::app_role)
+  );