feat: 树状视图路径压缩 - 单子节点文件夹自动合并

文件夹只有 1 个子节点时合并名称, 避免不必要的层级展开:
- a:b:c:d (单个 key) 直接显示为 a:b:c:d 而非 4 层嵌套
- a:b:c + a:b:d 仍展开为 a > b > {c, d} (b 有 2 个子节点)
- a:b:c + a:d:e 显示为 a > {b:c, d:e} (b/d 各 1 子节点, 合并)

src/renderer/src/components/KeyList.vue

@@ -452,7 +452,27 @@ const treeData = computed<TreeNode[]>(() => {
     updateCounts(node)
   }
 
-  return root
+  // Compress: merge folders that have exactly 1 child into a single node
+  // e.g. a > b > c (single key "a:b:c") becomes one leaf "a:b:c"
+  function compress(nodes: TreeNode[]): TreeNode[] {
+    return nodes.map(node => {
+      if (node.isLeaf) return node
+      const children = compress(node.children)
+      if (children.length === 1) {
+        const child = children[0]
+        return {
+          name: node.name + separator + child.name,
+          fullPath: child.fullPath,
+          isLeaf: child.isLeaf,
+          children: child.children,
+          count: child.count,
+        }
+      }
+      return { ...node, children }
+    })
+  }
+
+  return compress(root)
 })
 
 function isFolderExpanded(path: string): boolean {