Encode and Decode using the libwebp library via WASM with animation support

[bep]

Fixes #10030
Fixes #8500
Fixes #12843
Fixes #8879
Fixes #12842

Some issues left TODO:

• Issue with animated GIFs that I seem to have somehow broken.

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[bep]

As to performance:

• I have pushed an update that uses Wazero's latest con current compiler, which gets the "init WASM" step down from 130ms to 70ms on my MacBook. This is more or less the diff I see when building your test site with this branch and the master branch.
• In the final setup we will also cache the comiled WASM files to disk (like we do for Katex) and, also, if you have the images cached to disk, it will be as fast as before.

[jmooring]

Other than a stray debug statement, this looks good to me.

[Copilot]

Pull request overview

This PR migrates WebP image encoding and decoding from native Go libraries to a WASM-based implementation using libwebp, adding support for animated WebP images. The change removes the dependency on the "extended" build for WebP support, making it available in all builds.

Key changes:

• Replaces native WebP codec with WASM-based libwebp implementation
• Adds animation support for WebP images
• Removes extended build requirement for WebP functionality

Reviewed changes

Copilot reviewed 36 out of 57 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
tpl/images/images.go	Updates image config decoding to use new codec interface
resources/resource_spec.go	Integrates WASM dispatchers and exposes Imaging field
resources/images/webp/webp.go	Removes old extended build WebP encoder
resources/images/webp/webp_notavailable.go	Removes old non-extended build WebP stub
resources/images/config.go	Updates WebP version and documentation
resources/images/imagetesting/testing.go	Refactors to use new codec with animation support
resources/images/images_golden_integration_test.go	Adds comprehensive WebP processing tests
resources/image_extended_test.go	Removes obsolete extended-only WebP test
resources/testdata/webp/*	Adds WebP test fixtures (binary files)
resources/images/testdata/images_golden/process/webp/*	Adds golden image test files (binary files)

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[bep]

@gemini-code-assist review

[gemini-code-assist]

Code Review

This pull request introduces WebP image processing using a WebAssembly (WASM) module, replacing the previous cgo-based implementation. This change adds support for animated WebP images. The implementation involves a new RPC-like protocol over stdin/stdout to communicate between Go and the C code in the WASM module, handling both JSON metadata and binary image data.

The overall implementation is well-structured and impressive. I've found a couple of related issues regarding the conversion between animated image formats, which I've detailed in my comments. Specifically, the conversion from animated WebP to animated GIF is not correctly implemented, and the himage.ImageFrames interface needs to be improved to support this correctly.

[bep]

@gemini-code-assist review

[gemini-code-assist]

Code Review

This pull request introduces WebP image processing support using a WebAssembly (WASM) module, replacing the previous CGo-based implementation. This is a significant improvement for portability. The changes include a new communication protocol between Go and the WASM module to handle binary data streams, new interfaces for animated images, and a centralization of image codec logic. The implementation is extensive and well-structured. I've found one critical issue in the C code of the WASM module that could lead to a crash. Other than that, the changes look solid.

[bep]

@gemini-code-assist review

[gemini-code-assist]

Code Review

This pull request introduces a significant and well-executed refactoring to handle WebP image processing using WebAssembly (WASM) instead of CGo. This change enables WebP support, including animations, across all Hugo versions, not just the extended one. The implementation includes a new WASM RPC communication layer that supports binary data streams, a generic image codec abstraction, and new interfaces for animated images. The changes are extensive and touch many parts of the codebase related to image processing and resource handling. I've found one critical issue related to goroutine variable capturing that needs to be addressed. Otherwise, the changes look solid and the addition of tests is commendable.