Feishu Lite 0.1.8

修复图片分栏在多段落或不同嵌入结构下上下堆放的问题：整个分栏块现在共用一个网格，每张图片独立占格。图片异步加载后及时更新空分栏状态；编辑和阅读视图的监听随视图卸载释放。通过 320 / 360 / 390 / 768px 宽度、2 / 3 / 4 栏及三种图片语法组合的 36 组渲染检查，手机真机效果待更新后验证。

Fixed image grids stacking vertically across separate paragraphs or embed structures. Images now share one grid across the callout. Empty-state markers stay in sync with asynchronous image loading, and observers are disposed with reading and editor views. Verified 36 rendering combinations across 320 / 360 / 390 / 768px widths, 2 / 3 / 4 columns, and three image layouts. Physical-device validation remains pending.