style(editor): 优化插入索引计算的代码格式

- 调整了插入索引计算代码的缩进和换行
- 增强了代码的可读性和结构清晰度
- 保持原有逻辑未做功能性修改

src/views/editor/components/EditorPanel/components/EditAreaContextMenuModal/functionals/index.ts

@@ -558,7 +558,14 @@ export function useEditAreaContextMenu(props: EditAreaContextMenuProps, emit: (e
                                 targetItem.node.mixedContent.push({ type: 'text', text: textVal })
                             } else if (targetItem.parent) {
                                 const mixedIdx = targetItem.parent.mixedContent.findIndex((m: any) => m.nodeId === realId)
-                                const insertIdx = mode === 'above' ? (mixedIdx !== -1 ? mixedIdx : 0) : (mixedIdx !== -1 ? mixedIdx + 1 : targetItem.parent.mixedContent.length)
+                                const insertIdx =
+                                    mode === 'above'
+                                        ? mixedIdx !== -1
+                                            ? mixedIdx
+                                            : 0
+                                        : mixedIdx !== -1
+                                          ? mixedIdx + 1
+                                          : targetItem.parent.mixedContent.length
                                 targetItem.parent.mixedContent.splice(insertIdx, 0, { type: 'text', text: textVal })
                             }
                             targetItem.node.textContent = targetItem.node.mixedContent