Add automated gem release workflow via GitHub Actions

Uses RubyGems trusted publishing (OIDC) to publish all 12 gems
on tag push. Creates a draft GitHub Release with auto-generated
release notes.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: jnunemaker

.github/workflows/release.yml

@@ -0,0 +1,56 @@
+name: Release
+
+on:
+  push:
+    tags:
+      - 'v*'
+
+jobs:
+  release:
+    runs-on: ubuntu-latest
+    environment: Rubygems
+    permissions:
+      id-token: write   # RubyGems trusted publishing (OIDC)
+      contents: write   # Create GitHub Releases
+    steps:
+      - uses: actions/checkout@v6
+
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: '3.3'
+
+      - name: Build all gems
+        run: |
+          for gemspec in *.gemspec; do
+            gem build "$gemspec"
+          done
+          mkdir -p pkg
+          mv *.gem pkg/
+          echo "Built gems:"
+          ls -la pkg/
+
+      - name: Configure RubyGems credentials
+        uses: rubygems/configure-rubygems-credentials@main
+        with:
+          audience: 'https://rubygems.org'
+
+      - name: Publish core flipper gem
+        run: gem push pkg/flipper-[0-9]*.gem
+
+      - name: Publish all other gems
+        run: |
+          for gem_file in pkg/flipper-*.gem; do
+            basename="$(basename "$gem_file")"
+            if [[ "$basename" =~ ^flipper-[0-9] ]]; then
+              continue
+            fi
+            echo "Pushing $basename..."
+            gem push "$gem_file"
+          done
+
+      - name: Create draft GitHub Release
+        uses: softprops/action-gh-release@v2
+        with:
+          draft: true
+          generate_release_notes: true
+          files: pkg/*.gem

.gitignore

@@ -24,3 +24,4 @@ bin
 .tool-versions
 tags
 node_modules
+.claude