ci: add github action for building extension zip and crx

.github/workflows/build-extension.yml

@@ -0,0 +1,62 @@
+name: Build Chrome Extension
+
+on:
+  push:
+    branches: [ "main" ]
+    tags: [ "v*.*.*" ]
+  pull_request:
+    branches: [ "main" ]
+
+permissions:
+  contents: write
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout Code
+        uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: 20
+
+      - name: Create Extension ZIP
+        run: |
+          cd extension
+          zip -r ../opencli-extension.zip .
+
+      - name: Create Extension CRX
+        run: |
+          npm install -g crx3
+          if [ -n "${{ secrets.CRX_PRIVATE_KEY }}" ]; then
+            echo "Found CRX_PRIVATE_KEY, signing extension..."
+            echo "${{ secrets.CRX_PRIVATE_KEY }}" > crx-key.pem
+            crx3 pack extension -o opencli-extension.crx -p crx-key.pem
+            rm crx-key.pem
+          else
+            echo "No CRX_PRIVATE_KEY configured. Generating CRX with a temporary random key..."
+            crx3 pack extension -o opencli-extension.crx
+          fi
+
+      - name: Upload Artifacts (Action Run)
+        uses: actions/upload-artifact@v4
+        with:
+          name: opencli-extension-build
+          path: |
+            opencli-extension.zip
+            opencli-extension.crx
+          retention-days: 7
+
+      - name: Attach to GitHub Release
+        if: startsWith(github.ref, 'refs/tags/')
+        uses: softprops/action-gh-release@v2
+        with:
+          files: |
+            opencli-extension.zip
+            opencli-extension.crx
+          draft: false
+          prerelease: false
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}