Publish GitHub releases automatically from main

.github/workflows/build-release.yml

@@ -30,3 +30,87 @@ jobs:
           path: dist/*.zip
           if-no-files-found: error
           retention-days: 14
+
+  publish-release:
+    name: Publish GitHub release
+    if: github.event_name == 'push' && github.ref == 'refs/heads/main'
+    needs: build-release
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+    permissions:
+      contents: write
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v7
+        with:
+          fetch-depth: 0
+
+      - name: Download release package
+        uses: actions/download-artifact@v8
+        with:
+          name: prettyblocks-${{ github.sha }}
+          path: dist
+
+      - name: Prepare release metadata
+        id: release
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          set -Eeuo pipefail
+
+          version=$(awk -F"'" '/\$this->version[[:space:]]*=/{print $2; exit}' prettyblocks.php)
+          if [[ ! $version =~ ^[0-9]+\.[0-9]+\.[0-9]+([.+-][0-9A-Za-z.-]+)?$ ]]; then
+            echo "Unable to read a valid semantic version from prettyblocks.php." >&2
+            exit 1
+          fi
+
+          test -s dist/prettyblocks.zip
+          sha256sum dist/prettyblocks.zip > dist/prettyblocks.zip.sha256
+
+          previous_tag=$(gh release list \
+            --exclude-drafts \
+            --exclude-pre-releases \
+            --limit 1 \
+            --json tagName \
+            --jq '.[0].tagName // empty')
+
+          if [ -n "$previous_tag" ]; then
+            commit_range="${previous_tag}..${GITHUB_SHA}"
+          else
+            commit_range="$GITHUB_SHA"
+          fi
+
+          {
+            echo '## Contributors'
+            echo
+            git log --format='%aN%x09%aE' "$commit_range" \
+              | awk -F '\t' '!seen[tolower($2)]++ { print $1 }' \
+              | sort -fu \
+              | while IFS= read -r contributor; do
+                  printf -- '- %s\n' "$contributor"
+                done
+          } > release-notes-prefix.md
+
+          echo "version=$version" >> "$GITHUB_OUTPUT"
+
+      - name: Publish release
+        env:
+          GH_TOKEN: ${{ github.token }}
+          VERSION: ${{ steps.release.outputs.version }}
+        run: |
+          set -Eeuo pipefail
+
+          if gh release view "$VERSION" >/dev/null 2>&1; then
+            echo "Release $VERSION already exists; nothing to publish."
+            exit 0
+          fi
+
+          gh release create "$VERSION" \
+            'dist/prettyblocks.zip#PrettyBlocks module ZIP' \
+            'dist/prettyblocks.zip.sha256#SHA-256 checksum' \
+            --target "$GITHUB_SHA" \
+            --title "$VERSION" \
+            --generate-notes \
+            --notes "$(cat release-notes-prefix.md)" \
+            --fail-on-no-commits