feat(复习): 节点选择交互 + 移除 session 维度

- MindMapViewer 新增 selectable 模式，点击节点 emit node-select 事件
- ReviewRecall.vue 移除会话选择器，改为节点选择交互
- 支持 URL ?focusPath= 参数自动预设复习起点
- 节点选择弹窗确认后回忆导图根节点=选中节点标题
- ReviewDetail 和 Welcome 中调用 findNode API 匹配节点后跳转
- API: recallCompare 使用 focusPath 替代 sessionNum
- API: 新增 findNode 端点

src/components/Welcome.vue

@@ -99,6 +99,29 @@ const openRecallDetail = () => {
   router.push(`/review/detail/${group.navigateType}/${group.navigateId}`);
 };
 
+/** 从回忆卡片跳转到回忆复习页（先匹配标准导图节点） */
+const goToRecallFromCard = async () => {
+  const group = recallCard.value.group;
+  if (!group) return;
+  recallCard.value.visible = false;
+  const tn = group.taskNum;
+  const content = group.content || "";
+  if (tn && content) {
+    try {
+      const { findNode } = await import("@/api/standardMindMap");
+      const res = await findNode(tn, content.substring(0, 500));
+      const data = res?.data;
+      if (data?.path) {
+        router.push(`/review/recall/${tn}?focusPath=${encodeURIComponent(data.path)}`);
+        return;
+      }
+    } catch { /* fall through */ }
+    router.push(`/review/recall/${tn}`);
+  } else {
+    router.push("/review");
+  }
+};
+
 const startStudy = () => {
   router.push("/study");
 };
@@ -197,6 +220,7 @@ onMounted(() => {
         回忆好了，展开对照
       </el-button>
       <el-button v-else type="success" @click="openRecallDetail">进入详情页</el-button>
+      <el-button type="success" plain @click="goToRecallFromCard">前往回忆复习</el-button>
       <el-button @click="recallCard.visible = false">关闭</el-button>
     </template>
   </el-dialog>