Add CI workflow for multi-OS build and release

Author: beNative

.github/workflows/build.yml

@@ -0,0 +1,65 @@
+name: CI / Multi-OS Build
+
+on:
+  push:
+    branches: [ main ]
+    tags:     [ 'v*' ]   # push a version tag to publish a release
+  pull_request:
+
+jobs:
+  build:
+    name: Build (${{ matrix.os }} / Node ${{ matrix.node }})
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os:   [ubuntu-latest, windows-latest, macos-latest]
+        node: [20]   # add more versions if you want to test multiple
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Setup Node
+        uses: actions/setup-node@v4
+        with:
+          node-version: ${{ matrix.node }}
+          cache: npm   # npm|yarn|pnpm
+
+      - name: Install deps
+        run: npm ci
+
+      - name: Test
+        run: npm test --if-present
+
+      - name: Build
+        run: npm run build --if-present
+
+      - name: Package
+        run: npm run package --if-present
+        # e.g. produce ./dist/<platform> files
+
+      - name: Upload build artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: ${{ runner.os }}-build
+          path: |
+            dist/**
+            !**/*.map
+          retention-days: 14
+
+  release:
+    name: Release (attach all builds)
+    needs: build
+    if: startsWith(github.ref, 'refs/tags/v')
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+    steps:
+      - uses: actions/download-artifact@v4
+        with:
+          path: ./artifacts
+
+      - name: Create GitHub Release and upload assets
+        uses: ncipollo/release-action@v1
+        with:
+          tag: ${{ github.ref_name }}
+          generateReleaseNotes: true
+          artifacts: "artifacts/**/*"