fix: 连线位置偏移修复 - 改用 offsetLeft/offsetTop 替代 getBoundingClientRect

根因: getBoundingClientRect 返回屏幕坐标（受 scale 影响），
初始定位过程中 scale 从 1→0.45 变化时，连线在中间状态计算，
导致坐标与最终布局不匹配。

修复: 使用 offsetLeft/offsetTop 遍历 offsetParent 链获取本地坐标，
完全不受 CSS transform/scale 影响，消除 scale 依赖。

components/tree/tree-layout.tsx

@@ -150,7 +150,7 @@ export function TreeLayout({
     return checkHidden(nodeId)
   }, [getMember, collapsedNodes])
 
-  // 计算所有连线位置（使用 requestAnimationFrame 批量计算，避免 layout thrashing）
+  // 计算所有连线位置（使用 offsetLeft/offsetTop 获取本地坐标，不受 scale 影响）
   const rafIdRef = useRef<number | null>(null)
   const calculateConnections = useCallback(() => {
     if (rafIdRef.current !== null) {
@@ -158,9 +158,22 @@ export function TreeLayout({
     }
     rafIdRef.current = requestAnimationFrame(() => {
       rafIdRef.current = null
+      const container = containerRef.current
+      if (!container || nodeRefs.current.size === 0) return
+
+      // 辅助函数：获取元素相对于容器的本地坐标（不受 scale/transform 影响）
+      const getLocalRect = (el: HTMLElement) => {
+        let top = 0, left = 0
+        let node = el
+        while (node && node !== container) {
+          top += node.offsetTop
+          left += node.offsetLeft
+          node = node.offsetParent as HTMLElement
+        }
+        return { top, left, width: el.offsetWidth, height: el.offsetHeight }
+      }
+
       const newConnections: Connection[] = []
-      const containerRect = containerRef.current?.getBoundingClientRect()
-      if (!containerRect || nodeRefs.current.size === 0) return
 
       nodeRefs.current.forEach((nodeElement, nodeId) => {
         const member = getMember(nodeId)
@@ -168,22 +181,22 @@ export function TreeLayout({
         if (collapsedNodes.has(nodeId)) return
         if (isNodeHiddenByCollapse(nodeId)) return
         if (!document.body.contains(nodeElement)) return
-        const parentRect = nodeElement.getBoundingClientRect()
+        const parentRect = getLocalRect(nodeElement)
         if (parentRect.width === 0 || parentRect.height === 0) return
 
-        const parentCenterX = (parentRect.left + parentRect.width / 2 - containerRect.left) / scale
-        const parentBottomY = (parentRect.bottom - containerRect.top) / scale
+        const parentCenterX = parentRect.left + parentRect.width / 2
+        const parentBottomY = parentRect.top + parentRect.height
 
         const childPositions = member.childrenIds
           .map(childId => {
             const childElement = nodeRefs.current.get(childId)
             if (!childElement || !document.body.contains(childElement)) return null
-            const childRect = childElement.getBoundingClientRect()
+            const childRect = getLocalRect(childElement)
             if (childRect.width === 0 || childRect.height === 0) return null
             return {
               id: childId,
-              centerX: (childRect.left + childRect.width / 2 - containerRect.left) / scale,
-              topY: (childRect.top - containerRect.top) / scale
+              centerX: childRect.left + childRect.width / 2,
+              topY: childRect.top
             }
           })
           .filter(Boolean) as Array<{ id: string; centerX: number; topY: number }>
@@ -218,9 +231,10 @@ export function TreeLayout({
 
       setConnections(newConnections)
     })
-  }, [getMember, collapsedNodes, isNodeHiddenByCollapse, scale])
+  }, [getMember, collapsedNodes, isNodeHiddenByCollapse])
 
   // 使用 useLayoutEffect 在 DOM 更新后立即计算连线（替代 7 个 setTimeout）
+  // offsetLeft/offsetTop 不受 scale 影响，无需依赖 scale
   useLayoutEffect(() => {
     calculateConnections()
     // 双 rAF 确保浏览器完成布局后再计算