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/components/Study.vue

@@ -5,8 +5,11 @@ import router from "@/router";
 import { ElMessage } from "element-plus";
 import { getReviewTaskStatsByTask } from "@/api/review";
 import {
+  getPriorityWeights,
   getTaskApplications,
+  savePriorityWeights,
   updateTaskApplication,
+  type PriorityWeights,
   type TaskApplication,
 } from "@/api/tasks";
 
@@ -190,6 +193,62 @@ const removeTask = async () => {
   }
 };
 
+// ============ 优先级权重配置 ============
+const weightsDialogVisible = ref(false);
+const savingWeights = ref(false);
+const weightItems = ref([
+  { key: "urgencyWeight", label: "紧急性", value: 35 },
+  { key: "importanceWeight", label: "重要性", value: 25 },
+  { key: "contentDifficultyWeight", label: "内容难度", value: 20 },
+  { key: "futureValueWeight", label: "未来价值", value: 10 },
+  { key: "subjectivePriorityWeight", label: "主观优先级", value: 10 },
+]);
+
+const weightsSum = computed(() =>
+  weightItems.value.reduce((acc, item) => acc + item.value, 0)
+);
+
+const openWeightsDialog = async () => {
+  try {
+    const res = await getPriorityWeights();
+    const data = res?.data;
+    if (data) {
+      for (const item of weightItems.value) {
+        const v = data[item.key];
+        if (typeof v === "number") item.value = Math.round(v * 100);
+      }
+    }
+  } catch {
+    // 读取失败时保持默认值
+  }
+  weightsDialogVisible.value = true;
+};
+
+const saveWeights = async () => {
+  if (weightsSum.value !== 100) {
+    ElMessage.warning(`五项权重之和需为 100%，当前 ${weightsSum.value}%`);
+    return;
+  }
+  savingWeights.value = true;
+  try {
+    const payload = Object.fromEntries(
+      weightItems.value.map((item) => [item.key, item.value / 100])
+    ) as unknown as PriorityWeights;
+    const res = await savePriorityWeights(payload);
+    if (res?.code === 200) {
+      weightsDialogVisible.value = false;
+      ElMessage.success("权重已保存，任务优先级已重算");
+      await fetchTasks();
+    } else {
+      ElMessage.error(res?.message || "保存失败");
+    }
+  } catch (e: any) {
+    ElMessage.error(e.message || "请求失败");
+  } finally {
+    savingWeights.value = false;
+  }
+};
+
 onMounted(() => {
   fetchTasks();
 });
@@ -320,11 +379,32 @@ onMounted(() => {
           <el-button type="success" size="large" @click="startTask">开始任务</el-button>
           <el-button size="large" @click="addTask">添加任务</el-button>
           <el-button size="large" @click="changeTask">更新任务</el-button>
+          <el-button size="large" @click="openWeightsDialog">权重配置</el-button>
           <el-button type="danger" size="large" @click="removeTask">删除任务</el-button>
         </aside>
       </main>
     </div>
   </section>
+
+  <el-dialog v-model="weightsDialogVisible" title="优先级权重配置" width="560px">
+    <p class="weights-hint">
+      调整五个维度在优先级计算中的占比，保存后全部任务将按新权重重新排序。
+    </p>
+    <div v-for="item in weightItems" :key="item.key" class="weight-row">
+      <span class="weight-label">{{ item.label }}</span>
+      <el-slider v-model="item.value" :min="0" :max="100" :step="5" class="weight-slider" />
+      <span class="weight-value">{{ item.value }}%</span>
+    </div>
+    <div class="weights-sum" :class="{ 'sum-error': weightsSum !== 100 }">
+      合计：{{ weightsSum }}%（需为 100%）
+    </div>
+    <template #footer>
+      <el-button @click="weightsDialogVisible = false">取消</el-button>
+      <el-button type="success" :loading="savingWeights" :disabled="weightsSum !== 100" @click="saveWeights">
+        保存并重算
+      </el-button>
+    </template>
+  </el-dialog>
 </template>
 
 <style scoped>
@@ -334,6 +414,51 @@ onMounted(() => {
   gap: 14px;
 }
 
+.weights-hint {
+  margin: 0 0 14px;
+  font-size: 13px;
+  color: var(--text-secondary);
+}
+
+.weight-row {
+  display: flex;
+  align-items: center;
+  gap: 14px;
+  margin-bottom: 6px;
+}
+
+.weight-label {
+  flex-shrink: 0;
+  width: 80px;
+  font-size: 14px;
+  color: var(--text-primary);
+}
+
+.weight-slider {
+  flex: 1;
+}
+
+.weight-value {
+  flex-shrink: 0;
+  width: 44px;
+  text-align: right;
+  font-size: 13px;
+  color: var(--green-800);
+  font-weight: 600;
+}
+
+.weights-sum {
+  margin-top: 8px;
+  text-align: right;
+  font-size: 13px;
+  color: var(--green-800);
+  font-weight: 600;
+}
+
+.weights-sum.sum-error {
+  color: #c62828;
+}
+
 .layout-grid {
   display: grid;
   grid-template-columns: 280px 1fr;