feat: 成长路径管理添加拖拽排序功能

- 已选课程支持拖拽调整顺序
- 支持跨阶段拖拽移动课程
- 拖拽时显示视觉反馈（高亮线条）
- 拖拽到空阶段时显示占位提示
- 自动更新课程排序编号

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/src/views/manager/growth-path-management.vue

@@ -341,6 +341,10 @@
                   v-for="(stage, stageIndex) in editingPath.stages" 
                   :key="stageIndex"
                   class="stage-section"
+                  :class="{ 'stage-drag-over': dragOverStage === stage.name }"
+                  @dragover.prevent="handleStageDragOver($event, stage.name)"
+                  @dragleave="handleStageDragLeave($event)"
+                  @drop.stop="handleNodeDrop($event, stage.name)"
                 >
                   <div class="stage-header">
                     <span>{{ stage.name }}</span>
@@ -353,8 +357,19 @@
                       v-for="(node, nodeIndex) in getStageNodes(stage.name)" 
                       :key="node.course_id"
                       class="node-item"
+                      :class="{ 
+                        'is-dragging': draggingNode?.course_id === node.course_id,
+                        'drag-over-top': dragOverNode?.course_id === node.course_id && dragOverPosition === 'top',
+                        'drag-over-bottom': dragOverNode?.course_id === node.course_id && dragOverPosition === 'bottom'
+                      }"
+                      draggable="true"
+                      @dragstart="handleNodeDragStart($event, node, stage.name)"
+                      @dragend="handleNodeDragEnd"
+                      @dragover.prevent="handleNodeDragOver($event, node)"
+                      @dragleave="handleNodeDragLeave"
+                      @drop.stop="handleNodeDropOnNode($event, node, stage.name)"
                     >
-                      <div class="node-drag-handle">
+                      <div class="node-drag-handle" @mousedown.stop>
                         <el-icon><Rank /></el-icon>
                       </div>
                       <div class="node-content">
@@ -377,6 +392,7 @@
                           size="small" 
                           style="width: 90px"
                           placeholder="阶段"
+                          @change="handleNodeStageChange(node)"
                         >
                           <el-option 
                             v-for="s in editingPath.stages" 
@@ -398,8 +414,10 @@
                     <div 
                       v-if="getStageNodes(stage.name).length === 0" 
                       class="stage-empty"
+                      :class="{ 'stage-empty-active': dragOverStage === stage.name }"
                     >
-                      拖拽或点击课程添加到此阶段
+                      <el-icon><Plus /></el-icon>
+                      拖拽课程到此阶段
                     </div>
                   </div>
                 </div>
@@ -494,6 +512,13 @@ const courseCategory = ref('')
 const isDragging = ref(false)
 const isDraggingOver = ref(false)
 
+// 节点拖拽排序状态
+const draggingNode = ref<CreateGrowthPathNode | null>(null)
+const draggingFromStage = ref<string>('')
+const dragOverNode = ref<CreateGrowthPathNode | null>(null)
+const dragOverPosition = ref<'top' | 'bottom'>('bottom')
+const dragOverStage = ref<string>('')
+
 // 基础数据
 const positions = ref<Position[]>([])
 const courses = ref<Course[]>([])
@@ -942,6 +967,255 @@ const removeNode = (node: CreateGrowthPathNode) => {
   }
 }
 
+/**
+ * 节点阶段变更时重新排序
+ */
+const handleNodeStageChange = (node: CreateGrowthPathNode) => {
+  // 阶段变更后自动调整到该阶段的末尾
+  reorderNodes()
+}
+
+/**
+ * 重新排序节点（按阶段分组）
+ */
+const reorderNodes = () => {
+  if (!editingPath.value) return
+  // 按阶段顺序重新排列
+  const stageOrder = editingPath.value.stages.map(s => s.name)
+  editingPath.value.nodes.sort((a, b) => {
+    const stageIndexA = stageOrder.indexOf(a.stage_name)
+    const stageIndexB = stageOrder.indexOf(b.stage_name)
+    if (stageIndexA !== stageIndexB) {
+      return stageIndexA - stageIndexB
+    }
+    return (a.order_num || 0) - (b.order_num || 0)
+  })
+  // 更新 order_num
+  editingPath.value.nodes.forEach((node, index) => {
+    node.order_num = index + 1
+  })
+}
+
+// ========== 节点拖拽排序 ==========
+
+/**
+ * 节点开始拖拽
+ */
+const handleNodeDragStart = (event: DragEvent, node: CreateGrowthPathNode, stageName: string) => {
+  draggingNode.value = node
+  draggingFromStage.value = stageName
+  event.dataTransfer!.effectAllowed = 'move'
+  event.dataTransfer!.setData('node', JSON.stringify(node))
+  // 添加拖拽样式
+  const target = event.target as HTMLElement
+  setTimeout(() => {
+    target.classList.add('is-dragging')
+  }, 0)
+}
+
+/**
+ * 节点拖拽结束
+ */
+const handleNodeDragEnd = () => {
+  draggingNode.value = null
+  draggingFromStage.value = ''
+  dragOverNode.value = null
+  dragOverPosition.value = 'bottom'
+  dragOverStage.value = ''
+}
+
+/**
+ * 节点拖拽经过另一个节点
+ */
+const handleNodeDragOver = (event: DragEvent, targetNode: CreateGrowthPathNode) => {
+  if (!draggingNode.value || draggingNode.value.course_id === targetNode.course_id) return
+  
+  event.preventDefault()
+  dragOverNode.value = targetNode
+  
+  // 判断是放在目标节点的上方还是下方
+  const rect = (event.currentTarget as HTMLElement).getBoundingClientRect()
+  const midY = rect.top + rect.height / 2
+  dragOverPosition.value = event.clientY < midY ? 'top' : 'bottom'
+}
+
+/**
+ * 节点拖拽离开
+ */
+const handleNodeDragLeave = () => {
+  dragOverNode.value = null
+}
+
+/**
+ * 节点放置到另一个节点上
+ */
+const handleNodeDropOnNode = (event: DragEvent, targetNode: CreateGrowthPathNode, targetStage: string) => {
+  event.preventDefault()
+  
+  if (!draggingNode.value || !editingPath.value) return
+  if (draggingNode.value.course_id === targetNode.course_id) return
+  
+  // 找到拖拽节点的索引
+  const fromIndex = editingPath.value.nodes.findIndex(n => n.course_id === draggingNode.value!.course_id)
+  if (fromIndex === -1) return
+  
+  // 从原位置移除
+  const [movedNode] = editingPath.value.nodes.splice(fromIndex, 1)
+  
+  // 更新阶段
+  movedNode.stage_name = targetStage
+  
+  // 找到目标节点的新索引（因为可能已经移除了一个元素）
+  const toIndex = editingPath.value.nodes.findIndex(n => n.course_id === targetNode.course_id)
+  
+  // 根据放置位置插入
+  if (dragOverPosition.value === 'top') {
+    editingPath.value.nodes.splice(toIndex, 0, movedNode)
+  } else {
+    editingPath.value.nodes.splice(toIndex + 1, 0, movedNode)
+  }
+  
+  // 重新计算 order_num
+  editingPath.value.nodes.forEach((node, index) => {
+    node.order_num = index + 1
+  })
+  
+  // 清理状态
+  handleNodeDragEnd()
+  ElMessage.success('排序已更新')
+}
+
+/**
+ * 阶段区域拖拽经过
+ */
+const handleStageDragOver = (event: DragEvent, stageName: string) => {
+  event.preventDefault()
+  dragOverStage.value = stageName
+}
+
+/**
+ * 阶段区域拖拽离开
+ */
+const handleStageDragLeave = (event: DragEvent) => {
+  // 检查是否真的离开了阶段区域
+  const rect = (event.currentTarget as HTMLElement).getBoundingClientRect()
+  const x = event.clientX
+  const y = event.clientY
+  if (x < rect.left || x > rect.right || y < rect.top || y > rect.bottom) {
+    dragOverStage.value = ''
+  }
+}
+
+/**
+ * 节点放置到阶段区域（空白处）
+ */
+const handleNodeDrop = (event: DragEvent, targetStage: string) => {
+  event.preventDefault()
+  
+  // 优先处理从课程库拖入的课程
+  const courseData = event.dataTransfer!.getData('course')
+  if (courseData) {
+    const course = JSON.parse(courseData) as Course
+    handleAddCourseToStage(course, targetStage)
+    dragOverStage.value = ''
+    return
+  }
+  
+  // 处理节点排序
+  if (!draggingNode.value || !editingPath.value) {
+    dragOverStage.value = ''
+    return
+  }
+  
+  // 移动节点到目标阶段末尾
+  const fromIndex = editingPath.value.nodes.findIndex(n => n.course_id === draggingNode.value!.course_id)
+  if (fromIndex === -1) return
+  
+  const [movedNode] = editingPath.value.nodes.splice(fromIndex, 1)
+  movedNode.stage_name = targetStage
+  
+  // 找到该阶段最后一个节点的位置，插入其后
+  const stageNodes = editingPath.value.nodes.filter(n => n.stage_name === targetStage)
+  if (stageNodes.length > 0) {
+    const lastNode = stageNodes[stageNodes.length - 1]
+    const lastIndex = editingPath.value.nodes.findIndex(n => n.course_id === lastNode.course_id)
+    editingPath.value.nodes.splice(lastIndex + 1, 0, movedNode)
+  } else {
+    // 该阶段为空，找到下一个阶段的第一个节点位置
+    const stageOrder = editingPath.value.stages.map(s => s.name)
+    const targetStageIndex = stageOrder.indexOf(targetStage)
+    let insertIndex = editingPath.value.nodes.length
+    
+    for (let i = targetStageIndex + 1; i < stageOrder.length; i++) {
+      const nextStageFirstNode = editingPath.value.nodes.find(n => n.stage_name === stageOrder[i])
+      if (nextStageFirstNode) {
+        insertIndex = editingPath.value.nodes.indexOf(nextStageFirstNode)
+        break
+      }
+    }
+    editingPath.value.nodes.splice(insertIndex, 0, movedNode)
+  }
+  
+  // 重新计算 order_num
+  editingPath.value.nodes.forEach((node, index) => {
+    node.order_num = index + 1
+  })
+  
+  handleNodeDragEnd()
+  ElMessage.success('已移动到' + targetStage)
+}
+
+/**
+ * 添加课程到指定阶段
+ */
+const handleAddCourseToStage = (course: Course, stageName: string) => {
+  if (!editingPath.value) return
+  if (isNodeAdded(course.id)) {
+    ElMessage.warning('该课程已添加')
+    return
+  }
+
+  // 找到该阶段最后一个节点的位置
+  const stageNodes = editingPath.value.nodes.filter(n => n.stage_name === stageName)
+  let insertIndex = editingPath.value.nodes.length
+  
+  if (stageNodes.length > 0) {
+    const lastNode = stageNodes[stageNodes.length - 1]
+    insertIndex = editingPath.value.nodes.indexOf(lastNode) + 1
+  } else {
+    // 该阶段为空，找到正确的插入位置
+    const stageOrder = editingPath.value.stages.map(s => s.name)
+    const targetStageIndex = stageOrder.indexOf(stageName)
+    
+    for (let i = targetStageIndex + 1; i < stageOrder.length; i++) {
+      const nextStageFirstNode = editingPath.value.nodes.find(n => n.stage_name === stageOrder[i])
+      if (nextStageFirstNode) {
+        insertIndex = editingPath.value.nodes.indexOf(nextStageFirstNode)
+        break
+      }
+    }
+  }
+
+  const newNode: CreateGrowthPathNode = {
+    course_id: course.id,
+    stage_name: stageName,
+    title: course.name || course.title || '',
+    description: course.description,
+    order_num: insertIndex + 1,
+    is_required: true,
+    estimated_days: Math.ceil((course.duration_hours || course.estimatedDuration || 2) / 2),
+  }
+
+  editingPath.value.nodes.splice(insertIndex, 0, newNode)
+  
+  // 重新计算 order_num
+  editingPath.value.nodes.forEach((node, index) => {
+    node.order_num = index + 1
+  })
+
+  ElMessage.success(`已添加到${stageName}`)
+}
+
 // ========== 生命周期 ==========
 onMounted(() => {
   loadPositions()
@@ -1316,6 +1590,14 @@ onMounted(() => {
 
           .stage-section {
             margin-bottom: 16px;
+            transition: all 0.2s ease;
+
+            &.stage-drag-over {
+              .stage-nodes {
+                background: #ecf5ff;
+                border-color: #667eea;
+              }
+            }
 
             .stage-header {
               display: flex;
@@ -1335,6 +1617,7 @@ onMounted(() => {
               border-radius: 0 0 6px 6px;
               padding: 8px;
               min-height: 50px;
+              transition: all 0.2s ease;
 
               .node-item {
                 display: flex;
@@ -1345,14 +1628,65 @@ onMounted(() => {
                 border: 1px solid #ebeef5;
                 border-radius: 6px;
                 margin-bottom: 8px;
+                cursor: grab;
+                transition: all 0.2s ease;
+                position: relative;
 
                 &:last-child {
                   margin-bottom: 0;
                 }
 
+                &:hover {
+                  border-color: #667eea;
+                  box-shadow: 0 2px 8px rgba(102, 126, 234, 0.15);
+                }
+
+                &:active {
+                  cursor: grabbing;
+                }
+
+                &.is-dragging {
+                  opacity: 0.5;
+                  background: #f5f7fa;
+                  border-style: dashed;
+                }
+
+                &.drag-over-top {
+                  &::before {
+                    content: '';
+                    position: absolute;
+                    top: -4px;
+                    left: 0;
+                    right: 0;
+                    height: 3px;
+                    background: linear-gradient(90deg, #667eea, #764ba2);
+                    border-radius: 2px;
+                    animation: pulse-line 1s infinite;
+                  }
+                }
+
+                &.drag-over-bottom {
+                  &::after {
+                    content: '';
+                    position: absolute;
+                    bottom: -4px;
+                    left: 0;
+                    right: 0;
+                    height: 3px;
+                    background: linear-gradient(90deg, #667eea, #764ba2);
+                    border-radius: 2px;
+                    animation: pulse-line 1s infinite;
+                  }
+                }
+
                 .node-drag-handle {
                   color: #c0c4cc;
                   cursor: move;
+                  transition: color 0.2s;
+
+                  &:hover {
+                    color: #667eea;
+                  }
                 }
 
                 .node-content {
@@ -1387,13 +1721,32 @@ onMounted(() => {
 
               .stage-empty {
                 text-align: center;
-                padding: 16px;
+                padding: 20px 16px;
                 color: #909399;
                 font-size: 13px;
+                border: 2px dashed #e4e7ed;
+                border-radius: 6px;
+                margin: 4px 0;
+                transition: all 0.2s ease;
+                display: flex;
+                align-items: center;
+                justify-content: center;
+                gap: 8px;
+
+                &.stage-empty-active {
+                  background: #ecf5ff;
+                  border-color: #667eea;
+                  color: #667eea;
                 }
               }
             }
           }
+
+          @keyframes pulse-line {
+            0%, 100% { opacity: 1; }
+            50% { opacity: 0.5; }
+          }
+      }
     }
   }