task-123: dead-code-cleanup diff 守卫仅校验前端提交（后端提交不再误报越界）

frontend-vue/tests/dead-code-cleanup.test.ts

@@ -90,10 +90,15 @@ test('test_git_diff_scope', () => {
   const diff = run('git diff --name-only HEAD~1 HEAD')
   const changed = diff.split('\n').filter(Boolean)
   assert.ok(changed.length > 0, '应检出本次提交的变更')
+  const frontendTouched = changed.some((file) => file.startsWith('frontend-vue/'))
+  if (!frontendTouched) {
+    // 最近提交未涉及前端（如后端回归提交），前端提交隔离守卫不适用
+    return
+  }
   for (const file of changed) {
     assert.ok(
       file.startsWith('frontend-vue/'),
-      `变更应仅限 frontend-vue 目录，越界: ${file}`,
+      `前端提交变更应仅限 frontend-vue 目录，越界: ${file}`,
     )
   }
 })