Fix: Skip composer install if composer.json doesn't exist

This allows the Docker image to be tested standalone with --version
without requiring a composer.json file to be present.

Fixes the Docker build test that runs the container without a project context.

Author: claude

entrypoint.sh

@@ -17,11 +17,15 @@ if [ "${REQUIRE_DEV}" != "true" ]; then
     COMPOSER_FLAGS="${COMPOSER_FLAGS} --no-dev"
 fi
 
-# Install project dependencies
-echo "::group::Installing project dependencies"
-# shellcheck disable=SC2086
-composer install ${COMPOSER_FLAGS}
-echo "::endgroup::"
+# Install project dependencies if composer.json exists
+if [ -f "composer.json" ]; then
+    echo "::group::Installing project dependencies"
+    # shellcheck disable=SC2086
+    composer install ${COMPOSER_FLAGS}
+    echo "::endgroup::"
+else
+    echo "::notice::No composer.json found, skipping dependency installation"
+fi
 
 # Build PHPArkitect flags
 PHPARKITECT_FLAGS=""