SVG runtime and compiler infra improvements

[scorsin-oai]

Description

This change contains some SVG related changes.

Compiler/Infra:

• pngquant and resvg are now always compiled from source. They are now bundled inside the Valdi Compiler Toolbox binary, removing the need for using git lfs for the resvg .a static libraries and the pngquant libraries. The compiler toolbox now has a --pngquant option which the Valdi compiler uses.
• WORKSPACE setup now requires a new valdi_initialize_rust_workspace() call. This is necessary to get the Rust Bazel dependencies needed to build pngquant and resvg from source.

Runtime:

• The <image> element now supports svgs. It can have a src that points to a URL that fetches SVG. The SVG is rasterized at runtime in a background thread after the image is loaded. This works on iOS, Android and SnapDrawing.
• The <animatedimage> element now also support svg. Unlike <image>, there is no rasterization, the SVG is drawn at full resolution every time the layer is redrawn (after an invalidation). That means that if the layer is being resized, it will render in full resolution in real time, it will always look sharp.

Type of Change

• Bug fix (non-breaking change that fixes an issue)
• Documentation improvement
• Performance optimization
• Test improvement
• Other (please describe)

Testing

• Tests pass locally (bazel test //...)
• Added/updated tests for changes (if applicable)
• Tested on multiple platforms (iOS/Android/Web/macOS as applicable)
• Manual testing performed (describe below)

Testing Details

Checklist

• Code follows project style guidelines
• Documentation updated (if needed)
• No breaking changes (or documented in description)
• Commit messages follow conventional format
• No secrets, API keys, or internal URLs included

Related Issues

Additional Context

[github-actions]

Sensitive Files Detected

📦 Dependency change — Modifies the Bazel module graph — needs runtime team review after import.

📎 Prebuilt binary — Changes a prebuilt binary — requires verification of provenance.

🔧 Build rules — Affects build rules for all Valdi consumers.

_{This is an automated notice. A maintainer will review after import.}