Forward default options from the parser factory

[Aurantium-47]

The documented parser(transform, options) API drops its second argument. For example, parser(undefined, { lossless: false }).processSync('a > b') returns a > b instead of a>b.

Forward the default options to Processor and expose the optional argument in the existing TypeScript overloads. The processor already merges defaults with per-call options. Four regression tests cover synchronous and asynchronous whitespace handling, a custom nesting limit, asynchronous rule mutation, and per-call overrides. Type checks cover omitted transforms, return inference, and the existing restriction on calling async processors synchronously.

Validation on Windows with Node 24.15.0:

• All four regression tests fail on the unchanged source and pass with this fix.
• Full suite: 800 passing; coverage 94.98% lines, 95.50% branches, 97.70% functions, meeting the configured thresholds.
• TypeScript build, type checks, lint, formatting of changed source files, and git diff --check pass. Lint reports two existing unnecessary-escape warnings in exceptions.mjs.

Developed and tested with OpenAI Codex assistance.