[Aurantium-47]

JSON5.stringify currently rereads an array's length after each element. A replacer that appends 2 while serializing [1] produces [1,2]; a replacer that truncates [1,2] to length 1 produces [1]. Native JSON.stringify produces [1] and [1,null], respectively.

Capture the array length before visiting its elements, consistent with the documented JSON-compatible API and ECMAScript's array serialization algorithm. Add regression tests for both mutations. Values are still read as each element is visited.

Validation:

• Both new assertions fail with the original source and pass with the fix.
• Full test suite: 180 passing, 100% coverage in all four metrics.
• npm run lint passes.
• Tested on Windows with Node 24.15.0. The local run disabled TAP 12's incompatible legacy ESM shim through a temporary external TAP configuration, and used LF for the CLI's shebang lint check. Neither workaround is included in the patch. The historical CI runtime matrix has not been run locally.

AI assistance: OpenAI Codex was used for investigation, implementation, and automated validation.

[jordanbtucker]

Thanks for this fix! Would you be interested in writing a PR for #390 ? It's the parse-version of this PR.