fix: add yalc fallback to ensure plugin is installed in CI

Add check after yalc-add to verify plugin was linked successfully.
If yalc failed (not uncommon with certain Node versions), automatically
fall back to using file:.. link so plugin is still available for tests.

This prevents 'plugin not installed' errors when yalc silently fails.

Author: MSACC

.github/workflows/tests.yml

@@ -40,6 +40,13 @@ jobs:
         run: yarn build
       - name: Add yalc package to the playground
         run: yarn playground:yalc-add
+      - name: Ensure plugin is available (fallback if yalc failed)
+        run: |
+          cd playground
+          if [ ! -d ".yalc/strapi-plugin-config-sync" ]; then
+            echo "Yalc link failed, using file link as fallback"
+            sed -i 's|"strapi-plugin-config-sync": "link:.yalc/strapi-plugin-config-sync"|"strapi-plugin-config-sync": "file:.."|' package.json
+          fi
       - name: Install dependencies playground
         run: cd playground && yarn install --unsafe-perm
       - name: Build playground