Add comprehensive built-in object support for the JavaScript engine: ## Infrastructure - NativeContext passed to native callbacks (GC access + this binding) - Object.prototype and Array.prototype stored in VM - CreateObject/CreateArray set prototype chains - Array literals now set length property ## Object built-ins - Constructor, Object.keys/values/entries/assign/create/is - Object.getPrototypeOf/getOwnPropertyNames/getOwnPropertyDescriptor - Object.defineProperty/freeze/seal/isFrozen/isSealed - Object.fromEntries/hasOwn - Object.prototype: hasOwnProperty/toString/valueOf ## Array built-ins - Native: push/pop/shift/unshift, indexOf/lastIndexOf/includes - Native: join/slice/concat/reverse/splice/fill/at/toString - Static: Array.isArray/from/of - JS preamble: map/filter/reduce/reduceRight/forEach - JS preamble: find/findIndex/some/every/sort/flat/flatMap ## Error built-ins - Error/TypeError/ReferenceError/SyntaxError/RangeError/URIError/EvalError - Prototype chain with name/message, Error.prototype.toString ## Global functions - parseInt/parseFloat/isNaN/isFinite 37 new tests covering all built-in categories. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>