Add Windows build workflow with manual trigger

Co-authored-by: jgarzik <[email protected]>

Author: Copilot

.github/workflows/windows-build.yml

@@ -0,0 +1,29 @@
+name: Windows Build
+
+on:
+  workflow_dispatch: {}
+
+env:
+  CARGO_TERM_COLOR: always
+  RUST_BACKTRACE: 1
+
+jobs:
+  windows-build:
+    runs-on: windows-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: System info
+        run: |
+          echo "=== Architecture ==="
+          systeminfo | findstr /B /C:"OS Name" /C:"OS Version" /C:"System Type"
+          echo "=== Toolchain ==="
+          rustc --version
+          cargo --version
+      - name: Fetch
+        run: cargo fetch
+      - name: Build
+        run: cargo build --release --verbose
+      - name: Run tests
+        run: cargo test --release --verbose
+      - name: Run fmt check
+        run: cargo fmt --all -- --check