Port JSON responses containing projected anonymous string arrays

Opt-in default-encoder/declaration-order port of fresh default JavaScriptSerializer responses with string properties and arrays from in-file Enumerable.Select expression-bodied anonymous string projections followed by ToArray. Require bound local provenance, explicit ASCII property names and all-string element properties; retain projection/materialization and capture response values once in order. Use the existing portable response helper and BCL reflection for the compiler-generated sealed element getters. Preserve null arrays/elements/strings, IEnumerable traversal and the default size/error policy. Leave unknown element provenance, DTOs, dynamic/nested/other properties, custom serializers, unsupported imports/owners, lambdas/queries and snapshots unchanged. Custom encoders/ampersand settings, localized errors, reflection property order, anonymous allocation identity and trimming behavior are not emulated. Separate opt-in; Core 3.0 or later.