GIF compressor engine source and build materials

All paths below are relative to /gif-compressor/v1/source/.

1. gifsicle-1.92.tar.gz: original Gifsicle C source, configure scripts and GPL license.
2. browser-wrapper.zip: the complete browser adaptation source, including
   src/gifsicle.js, src/gifsicle.wasm, src/build.js, rollup.config.js and LICENSE.
   The archived dist/gifsicle.min.js matches npm gifsicle-wasm-browser 1.5.19 byte for byte.
3. wasm-codecs.zip: upstream build infrastructure and its sources/licenses.
4. Dockerfile and build.sh: convenient copies of the Gifsicle build instructions.
5. prepare-gif-compressor.cjs: ImgTweak's worker extraction script.

The browser package's src/build.js packages its generated Emscripten glue and
WebAssembly into workerLocalUrl. The npm artifact contains this worker text.
ImgTweak extracts it as worker.js; it does not modify the compiled GIF algorithm.
The original source archive includes build settings and JavaScript adaptation.
The wasm-codecs build scripts document the Emscripten/Docker compiler setup.

To reproduce ImgTweak's standalone packaging: install gifsicle-wasm-browser@1.5.19
and run prepare-gif-compressor.cjs in the site's scripts directory. Engine source,
notices and licenses are served as separate files and are not loaded at page visit.
See ../SHA256.txt for checksums of distributed artifacts.