feat(预期)：学习预期闭环 + 权重配置 UI

- StartTask：新会话强制填写学习预期（不可跳过），页面顶部常驻展示可修改
- 结束会话弹窗：展示本次预期供对照，有残片时自动拉取 AI 聚合草稿作为编辑起点
- Study：常用操作增加权重配置——五维度滑块、合计校验 100%、保存后重算并刷新
- api：expectation / report-draft / priority-weights 接口

src/api/tasks.ts

@@ -42,3 +42,22 @@ export const updateTaskApplication = (
 export const deleteTaskApplication = (id: number) => {
   return request.del(`/tasks/applications/${id}`);
 };
+
+// ============ 优先级权重配置 ============
+
+export interface PriorityWeights {
+  urgencyWeight: number;
+  importanceWeight: number;
+  contentDifficultyWeight: number;
+  futureValueWeight: number;
+  subjectivePriorityWeight: number;
+}
+
+export const getPriorityWeights = () => {
+  return request.get("/tasks/priority-weights");
+};
+
+/** 保存权重配置并触发全部任务优先级重算 */
+export const savePriorityWeights = (weights: PriorityWeights) => {
+  return request.put("/tasks/priority-weights", weights);
+};