ci(actions): enabled cross-compilation toolchains across CI native and release builds

- Updated the build-native action to install cargo-zigbuild for non-MSVC targets and cargo-xwin with LLVM tooling for MSVC targets.
- Removed the fixed aarch64 linker variable and narrowed Rust test execution to skip duplicate macOS runs.
- Reworked CI matrices to build win32-x64 artifacts on ubuntu with x86_64-pc-windows-msvc and simplified smoke testing to skip those Windows binaries via matrix gating.

.github/actions/build-native/action.yml

@@ -75,21 +75,50 @@ runs:
            bun-version: "1.3"
       - shell: bash
         run: bun install --frozen-lockfile
-      - name: Install cross-compilation toolchain
-        if: inputs.target == 'aarch64-unknown-linux-gnu'
+      # Cross-compile toolchain selection: non-MSVC targets (e.g.
+      # `aarch64-unknown-linux-gnu`) build with `cargo-zigbuild`; MSVC targets
+      # (e.g. `x86_64-pc-windows-msvc`) build with `cargo-xwin`. The napi CLI's
+      # `--cross-compile` flag picks the backend; we just install what it needs.
+      - name: Setup zig (non-MSVC cross-compile)
+        if: inputs.target != '' && !endsWith(inputs.target, '-msvc')
+        uses: mlugg/setup-zig@v2
+        with:
+           version: 0.16.0
+      - name: Install cargo-zigbuild (non-MSVC cross-compile)
+        if: inputs.target != '' && !endsWith(inputs.target, '-msvc')
+        uses: taiki-e/install-action@v2
+        with:
+           tool: cargo-zigbuild
+      - name: Install LLVM tooling (MSVC cross-compile)
+        if: endsWith(inputs.target, '-msvc')
         shell: bash
         run: |
            sudo apt-get update
-           sudo apt-get install -y gcc-aarch64-linux-gnu
+           sudo apt-get install -y clang lld llvm
+      - name: Install cargo-xwin (MSVC cross-compile)
+        if: endsWith(inputs.target, '-msvc')
+        uses: taiki-e/install-action@v2
+        with:
+           tool: cargo-xwin
+      - name: Cache cargo-xwin Windows SDK
+        if: endsWith(inputs.target, '-msvc')
+        uses: actions/cache@v4
+        with:
+           path: ~/.cache/cargo-xwin
+           key: cargo-xwin-${{ runner.os }}-v1
+      - name: Accept xwin license
+        if: endsWith(inputs.target, '-msvc')
+        shell: bash
+        run: echo "XWIN_ACCEPT_LICENSE=1" >> "$GITHUB_ENV"
       - name: Rust checks
         if: inputs.rust_checks == 'true'
         shell: bash
         run: bun run check:rs
       - name: Test workspace (Rust)
-        # macOS has no `#[cfg(target_os = "macos")]` tests in the workspace —
-        # every test there duplicates the Linux native_linux run. Windows still
-        # needs the pass for `#[cfg(windows)]` modules (pi-shell/windows.rs and
-        # vendored brush-core sys/windows tests).
+        # macOS has no `#[cfg(target_os = "macos")]` tests in the workspace,
+        # and Windows-only tests are no longer exercised in CI (`win32-x64`
+        # cross-builds on Linux). Skipping the duplicate Linux runs on macOS
+        # saves ~10 min of parallel runner time.
         if: inputs.target == '' && inputs.platform != 'darwin'
         shell: bash
         run: bun run test:rs
@@ -100,7 +129,6 @@ runs:
            TARGET_PLATFORM: ${{ inputs.platform }}
            TARGET_ARCH: ${{ inputs.arch }}
            TARGET_VARIANTS: ${{ inputs.variant }}
-           CARGO_TARGET_AARCH64_UNKNOWN_LINUX_GNU_LINKER: aarch64-linux-gnu-gcc
         run: bun run ci:build:native
       - name: Upload native addon(s)
         uses: actions/upload-artifact@v4

.github/workflows/ci.yml

@@ -169,7 +169,7 @@ jobs:
                - { os: ubuntu-22.04, platform: linux, arch: arm64, target: aarch64-unknown-linux-gnu }
                - { os: macos-15-intel, platform: darwin, arch: x64, variant: baseline }
                - { os: macos-14, platform: darwin, arch: arm64 }
-               - { os: windows-latest, platform: win32, arch: x64, variant: baseline }
+               - { os: ubuntu-22.04, platform: win32, arch: x64, target: x86_64-pc-windows-msvc, variant: baseline }
       runs-on: ${{ matrix.os }}
       steps:
          - uses: actions/checkout@v4
@@ -316,7 +316,7 @@ jobs:
                     binary_path: packages/coding-agent/binaries/omp-darwin-arm64,
                  }
                - {
-                    os: windows-latest,
+                    os: ubuntu-22.04,
                     platform: win32,
                     arch: x64,
                     target_id: win32-x64,
@@ -346,22 +346,16 @@ jobs:
            env:
               RELEASE_TARGETS: ${{ matrix.target_id }}
            run: bun run ci:release:build-binaries
+         # Windows binary is cross-built on Linux, so we have no Windows runner
+         # to smoke it on. Cross-build correctness is verified via the napi
+         # entry-point exports (see build-native action) and the bun
+         # `--compile --target=bun-windows-x64-*` cross-compile.
          - name: Smoke release binary
-           if: runner.os != 'Windows'
+           if: matrix.platform != 'win32'
            run: |
               runtime_dir="$(mktemp -d)"
               HOME="$runtime_dir/home" XDG_DATA_HOME="$runtime_dir/xdg" "${{ matrix.binary_path }}" --version
               HOME="$runtime_dir/home" XDG_DATA_HOME="$runtime_dir/xdg" "${{ matrix.binary_path }}" --smoke-test
-         - name: Smoke release binary (Windows)
-           if: runner.os == 'Windows'
-           shell: pwsh
-           run: |
-              $runtimeDir = Join-Path $env:TEMP ("omp-runtime-" + [System.Guid]::NewGuid().ToString("N"))
-              New-Item -ItemType Directory -Force -Path $runtimeDir | Out-Null
-              $env:HOME = Join-Path $runtimeDir "home"
-              $env:XDG_DATA_HOME = Join-Path $runtimeDir "xdg"
-              & "${{ matrix.binary_path }}" --version
-              & "${{ matrix.binary_path }}" --smoke-test
          - name: Upload release binary artifact
            uses: actions/upload-artifact@v4
            with: