fix: add retry logic to composer install steps to resolve DNS timeout failures

Replace bare 'composer install' with ramsey/composer-install action (which
provides built-in retry, caching, and --prefer-dist) in code-quality.yml and
tests.yml. Add a 3-attempt shell retry loop in release.yml where --no-dev
--optimize-autoloader flags are required.

phpunit.yml already used ramsey/composer-install and is unaffected.

Closes #57

.github/workflows/release.yml

@@ -34,7 +34,12 @@ jobs:
           echo "VERSION=$VERSION" >> $GITHUB_ENV
 
       - name: Install dependencies
-        run: composer install --no-dev --optimize-autoloader
+        run: |
+          for i in 1 2 3; do
+            composer install --no-dev --optimize-autoloader --prefer-dist && break
+            echo "Composer install attempt $i failed, retrying in 15s..."
+            sleep 15
+          done
 
       - name: Create build directory
         run: |