Prepare opencode-ruby alpha8

.github/workflows/release.yml

@@ -21,4 +21,12 @@ jobs:
         with:
           ruby-version: "4.0"
           bundler-cache: true
+      - name: Verify tag matches gem version
+        env:
+          RELEASE_TAG: ${{ github.ref_name }}
+        run: >-
+          ruby -Ilib -ropencode/version -e
+          'expected = ENV.fetch("RELEASE_TAG").delete_prefix("v");
+          abort "tag #{expected.inspect} does not match gem #{Opencode::VERSION.inspect}"
+          unless Opencode::VERSION == expected'
       - uses: rubygems/release-gem@052cc82692552de3ef2b81fd670e41d13cba8092 # v1.4.0