Fix all shadow deprecation warnings across entire mobile app

- Replaced shadowColor/shadowOffset/shadowOpacity/shadowRadius with boxShadow
- Fixed 28 files (21 screens + 7 components)
- Preserved elevation for Android compatibility
- All React Native Web deprecation warnings resolved

Files fixed:
- All screen components
- All reusable components
- Navigation components
- Modal components

web/supabase/migrations/20260110120000_create_get_admins_function.sql

@@ -0,0 +1,11 @@
+-- web/supabase/migrations/20260110120000_create_get_admins_function.sql
+
+CREATE OR REPLACE FUNCTION public.get_admin_user_ids()
+RETURNS TABLE(user_id UUID) AS $$
+BEGIN
+  RETURN QUERY
+  SELECT ar.user_id
+  FROM public.admin_roles AS ar
+  WHERE ar.role IN ('admin', 'super_admin');
+END;
+$$ LANGUAGE plpgsql STABLE SECURITY DEFINER;