Reduce coupling between core and cli packages (#961)

Co-authored-by: Marat Boshernitsan <maratb@google.com>

packages/cli/vitest.config.ts

@@ -16,8 +16,10 @@ export default defineConfig({
       junit: 'junit.xml',
     },
     coverage: {
+      enabled: true,
       provider: 'v8',
       reportsDirectory: './coverage',
+      include: ['src/**/*'],
       reporter: [
         ['text', { file: 'full-text-summary.txt' }],
         'html',