Upgrade wuff to 0.2.9 with compatible version requirements in the layout
and renderer test dependencies. Add a regression proving that corrupt
Brotli data returns a decode error and preserves an existing font.
Validation:
- cargo fmt --all
- cargo clippy --workspace --all-targets --all-features -- -D warnings
- cargo nextest run --no-fail-fast: 17574 passed, 13 skipped
- Release verification: the previous SIGABRT sample renders with fallback;
valid-font screenshots remain byte-identical
Move Fontconfig matching, substitution policy, and the Fontique lookup cache into moli-system-fonts. Keep CSS family adaptation in moli-layout, migrate tests and fixtures, and retain the Skia notice in source comments.
ldm0