release: v0.4.8

[avifenesh]

Summary

• release the deep GTK4 accessibility-tree traversal fix from fix: traverse deep GTK4 accessibility trees #86
• release the degraded-compositor installer classification fix from fix: allow degraded compositor installs #88
• bump the Cargo, npm, lockfile, and advertised MCP versions to 0.4.8
• document both fixes and update changelog comparison links

Validation

• bash -n install.sh scripts/install_sh_test.sh
• installer regression suite (12/12)
• cargo fmt --all -- --check
• cargo check --locked --all-targets
• cargo clippy --locked --all-targets -- -D warnings
• cargo test --locked --no-fail-fast (237 library tests, 7 helper tests, 1 integration test)
• RUSTDOCFLAGS="-D warnings" cargo doc --locked --no-deps --document-private-items
• cargo publish --dry-run --locked --allow-dirty (64 files packaged and verified)
• MCP safety contract (18 tools, version 0.4.8)
• Zod MCP schema validation (18 tools)
• npm pack --dry-run (@agent-sh/computer-use-linux@0.4.8)

After merge, pushing tag v0.4.8 will run the repository release workflow for GitHub assets, crates.io, and npm.