docs: add attestation message to GitHub release message

.github/workflows/release.yml

@@ -33,10 +33,30 @@ jobs:
         with:
           subject-path: 'packages/mcp-server/dist/*'
 
+      - name: Get existing release body
+        id: get_release
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const release = await github.rest.repos.getRelease({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              release_id: ${{ github.event.release.id }}
+            });
+            return release.data.body || '';
+
       - name: Upload Release Artifacts
+        env:
+          GH_WORKFLOW_URL: https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}
+          EXISTING_BODY: ${{ steps.get_release.outputs.result }}
         uses: ncipollo/release-action@v1
         with:
           allowUpdates: true
-          omitBody: true
           omitName: true
           artifacts: "packages/obsidian-plugin/releases/obsidian-plugin-*.zip,packages/obsidian-plugin/main.js,packages/obsidian-plugin/manifest.json,packages/obsidian-plugin/styles.css,packages/mcp-server/dist/*"
+          body: |
+            ${{ env.EXISTING_BODY }}
+
+            ---
+            ✨ This release includes attested build artifacts.
+            📝 View attestation details in the [workflow run](${{ env.GH_WORKFLOW_URL }})