Add artifact structure verification step

.github/workflows/build-opencode-cli-docker.yml

@@ -76,6 +76,13 @@ jobs:
           path: opencode/packages/opencode/dist
           merge-multiple: true
 
+      - name: Verify artifact structure
+        run: |
+          echo "Contents of dist directory:"
+          ls -la opencode/packages/opencode/dist/
+          echo "Looking for opencode binary..."
+          find opencode/packages/opencode/dist -name "opencode" -type f 2>/dev/null || echo "Binary not found"
+
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
         with: