fix(@jimp/wasm-webp): initialize WebP WASM from disk in Node

[Aniketiitk21]

Summary

• fix @jimp/wasm-webp in Node by resolving the existing @jsquash/webp WASM files from disk and compiling them directly instead of relying on fetch(file://...)
• keep the browser path unchanged while caching compiled decoder and encoder modules for repeated use
• add a Node regression test that decodes the existing WebP fixture and round-trips an encoded WebP buffer

Root Cause

@jsquash/webp initializes its WASM modules through a fetch-based path that works in browsers, but in Node it resolves to a local file: URL. Node's fetch() cannot load that URL, so @jimp/wasm-webp fails during decoder or encoder initialization before any image work can happen.

What Changed

For Node only, @jimp/wasm-webp now:

• resolves the decoder and encoder .wasm assets with Module.createRequire(import.meta.url)
• reads and compiles those files with node:fs/promises and WebAssembly.compile
• chooses the SIMD encoder binary only when the current runtime supports SIMD
• resets failed init promises so a transient initialization error does not permanently poison the process

Impact

This keeps the existing @jsquash/webp integration and public API intact, but makes the package usable in Node again for both decoding and encoding WebP images.

Closes #1366

Validation

• pnpm --filter @jimp/types build
• pnpm --filter @jimp/wasm-webp build
• pnpm --filter @jimp/wasm-webp lint
• pnpm --filter @jimp/wasm-webp test -- --run