Add PR preview feature

.github/workflows/ci.yml

@@ -24,6 +24,7 @@ concurrency:
 
 permissions:
   contents: read
+  pull-requests: write
 
 env:
   COMPOSER_NO_INTERACTION: 1
@@ -172,3 +173,68 @@ jobs:
           token: ${{ secrets.CODECOV_TOKEN }}
           files: artifacts/coverage/clover.xml
           fail_ci_if_error: false
+
+  playground:
+    if: github.event_name == 'pull_request'
+    runs-on: ubuntu-latest
+    timeout-minutes: 2
+    permissions:
+      pull-requests: write
+    steps:
+      - name: Find existing Playground comment
+        uses: peter-evans/find-comment@v3
+        id: find-comment
+        with:
+          issue-number: ${{ github.event.pull_request.number }}
+          comment-author: 'github-actions[bot]'
+          body-includes: '<!-- wp-playground-link -->'
+
+      - name: Build Playground URL
+        if: steps.find-comment.outputs.comment-id == ''
+        id: playground-url
+        run: |
+          PLUGIN_URL="https://github.com/${{ github.repository }}/archive/refs/heads/${{ github.head_ref }}.zip"
+
+          BLUEPRINT=$(cat <<'BLUEPRINT_EOF'
+          {
+            "$schema": "https://playground.wordpress.net/blueprint-schema.json",
+            "preferredVersions": { "php": "latest", "wp": "latest" },
+            "siteOptions": { "blogname": "eXeLearning PR Test" },
+            "steps": [
+              { "step": "setSiteLanguage", "language": "es_ES" },
+              {
+                "step": "installPlugin",
+                "pluginData": { "resource": "url", "url": "PLUGIN_URL_PLACEHOLDER" },
+                "options": { "activate": true }
+              },
+              {
+                "step": "runPHP",
+                "code": "<?php require_once '/wordpress/wp-load.php'; global $wp_rewrite; $wp_rewrite->set_permalink_structure('/%postname%/'); $wp_rewrite->flush_rules(true); ?>"
+              }
+            ],
+            "features": { "networking": true },
+            "login": true,
+            "landingPage": "/wp-admin/upload.php"
+          }
+          BLUEPRINT_EOF
+          )
+
+          BLUEPRINT=$(echo "$BLUEPRINT" | sed "s|PLUGIN_URL_PLACEHOLDER|${PLUGIN_URL}|g")
+          ENCODED=$(echo "$BLUEPRINT" | base64 -w 0)
+          PLAYGROUND_URL="https://playground.wordpress.net/#${ENCODED}"
+          echo "url=${PLAYGROUND_URL}" >> $GITHUB_OUTPUT
+
+      - name: Add Playground link comment
+        if: steps.find-comment.outputs.comment-id == ''
+        uses: peter-evans/create-or-update-comment@v4
+        with:
+          issue-number: ${{ github.event.pull_request.number }}
+          body: |
+            <!-- wp-playground-link -->
+            ## Test in WordPress Playground
+
+            Test the plugin **with the code from this branch**:
+
+            **[Open in WordPress Playground](${{ steps.playground-url.outputs.url }})**
+
+            > ⚠️ The embedded eXeLearning editor is not available in this preview (requires build). All other plugin features (ELP upload, shortcode, Gutenberg block, preview) work normally.