test: stabilize vitest config and integration test environment

Fabric.Backend.Center/vitest.config.ts

@@ -0,0 +1,8 @@
+import { defineConfig } from 'vitest/config';
+
+export default defineConfig({
+  test: {
+    include: ['src/**/*.spec.ts', 'src/*.integration.spec.ts'],
+    exclude: ['dist/**', 'node_modules/**'],
+  },
+});