feat: publish ARM64 and x86-64 desktop binaries

[lucarlig]

Summary

• complete the release matrix with native ARM64 Windows alongside x86-64 Windows, Linux, and macOS
• build each explicit Rust target and smoke-test the resulting native binary before packaging
• publish matching cargo-binstall archives for all six OS/architecture combinations

Release targets

• x86_64-unknown-linux-gnu
• aarch64-unknown-linux-gnu
• x86_64-apple-darwin
• aarch64-apple-darwin
• x86_64-pc-windows-msvc
• aarch64-pc-windows-msvc

Verification

• actionlint .github/workflows/release.yml
• cargo fmt --all --check
• cargo metadata --locked --no-deps --format-version 1
• cargo build --release --locked --bin cf-integration --target aarch64-apple-darwin
• native binary help smoke test
• release archive contents and SHA-256 verification

Stacked on #7.