Editor Quick Checklist

Select 2-3 paragraphs, open block menu, convert to code block. Expected: merged into 1 code block, selection remains on that block.
Select 2-3 contiguous blocks, click move up/down. Expected: all selected blocks move together in one step.
Select 2-3 contiguous blocks, drag using the block handle. Expected: drag preview shows "will move N blocks", all blocks move together.
Select multiple blocks, run copy/delete/duplicate from block menu. Expected: operation applies to all selected blocks.
After each multi-block action, press Ctrl/Cmd + Z once. Expected: the full action is reverted in one undo step.
Open block menu and expand "查看快捷键". Expected: shortcuts are visible and menu remains usable.