fix: clear stale class task rows

src/views/teacherEnd/task/index.vue

@@ -63,6 +63,7 @@ async function loadTasks() {
     tasks.value = [];
     return;
   }
+  tasks.value = [];
   const res = await listClassTrainingTasks(classId.value, { enabledOnly: false });
   tasks.value = res.data || [];
 }

tests/task-publication.static.test.cjs

@@ -11,6 +11,7 @@ const api = read("src/api/teacher.js");
 assert(taskPage.includes("listClassTrainingTasks"), "task allocation must use training tasks as its data source");
 assert(taskPage.includes("listClassTrainingTasks"), "task allocation must load training tasks for the selected teaching class");
 assert(taskPage.includes("await listClassTrainingTasks(classId.value, { enabledOnly: false })"), "class task loading must request disabled and enabled tasks");
+assert(taskPage.includes("tasks.value = [];\n  const res = await listClassTrainingTasks"), "class task loading must clear prior class rows before requesting the selected class");
 assert(taskPage.includes("getTaskPublication"), "task allocation must load the selected class publication state");
 assert(taskPage.includes("tasks.value.map((task) => task.taskKey)"), "an unconfigured class must default to all tasks selected");
 assert(taskPage.includes("保存发布配置"), "task allocation must require an explicit save");