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/ReviewDetail.vue

@@ -12,12 +12,32 @@ import {
 } from "@/api/review";
 import { getSessionDetail } from "@/api/studySessions";
 import { updateFragments } from "@/api/reportFragments";
+import { findNode } from "@/api/standardMindMap";
 import { ElMessage } from "element-plus";
 import MarkdownRenderer from "@/components/MarkdownRenderer.vue";
 
 const route = useRoute();
 const router = useRouter();
 
+/** 调用 findNode API 匹配标准导图中的最近节点，跳转到回忆页 */
+const goToRecall = async () => {
+  if (!content.value || !content.value.trim()) {
+    router.push(`/review/recall/${taskNum.value}`);
+    return;
+  }
+  try {
+    const res = await findNode(taskNum.value, content.value.substring(0, 500));
+    const data = res?.data;
+    if (data?.path) {
+      router.push(`/review/recall/${taskNum.value}?focusPath=${encodeURIComponent(data.path)}`);
+    } else {
+      router.push(`/review/recall/${taskNum.value}`);
+    }
+  } catch {
+    router.push(`/review/recall/${taskNum.value}`);
+  }
+};
+
 const contentType = computed(() => route.params.type as string);
 const contentId = computed(() => Number(route.params.id));
 
@@ -327,7 +347,7 @@ watch(
             >
               <el-button type="success" :loading="mindMapUploading">上传导图文件</el-button>
             </el-upload>
-            <el-button type="success" size="small" @click="router.push(`/review/recall/${taskNum}`)">
+            <el-button type="success" size="small" @click="goToRecall">
               回忆复习
             </el-button>
             <el-tag v-if="mindMap?.fileFormat" size="small" effect="plain">