Add attestations

.github/workflows/release.yaml

@@ -15,7 +15,9 @@ jobs:
   build:
     runs-on: ubuntu-latest
     permissions:
+      id-token: write
       contents: write
+      attestations: write
     steps:
       - uses: actions/checkout@v4
 
@@ -28,6 +30,14 @@ jobs:
           npm ci
           npm run build
 
+      - name: Generate artifact attestation
+        uses: actions/attest@v4
+        with:
+          subject-path: |
+            main.js
+            manifest.json
+            styles.css
+
       - name: Release
         run: |
           TAG="${GITHUB_REF#refs/tags/}"