Restore placeholder creds

Author: benitav

demos/local-only-todolist/lib/app_config.dart

@@ -1,6 +1,6 @@
 // Enter your Supabase and PowerSync project details.
 class AppConfig {
-  static const String supabaseUrl = 'https://beaywnuieweznatavpeg.supabase.co';
-  static const String supabaseAnonKey = 'eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJzdXBhYmFzZSIsInJlZiI6ImJlYXl3bnVpZXdlem5hdGF2cGVnIiwicm9sZSI6ImFub24iLCJpYXQiOjE3MjU0NTk3OTAsImV4cCI6MjA0MTAzNTc5MH0.sb5_RBESMWbfnq_xaZy00T8Mia9lzY0-BBc7ZovS5t0';
-  static const String powersyncUrl = 'https://660fe3a331d70135abf2c626.powersync.journeyapps.com';
-}
+  static const String supabaseUrl = 'https://foo.supabase.co';
+  static const String supabaseAnonKey = 'foo';
+  static const String powersyncUrl = 'https://foo.powersync.journeyapps.com';
+}