Paste (copy/move) items

Copies or moves a batch of files/folders (siblings from one folder level) into a destination directory, optionally in a different accessible business node. Both modes resolve name collisions with numeric " (2)" suffixes — nothing is overwritten. Moving a folder into itself or its own subtree is rejected. Nothing can be pasted INTO a folder synced from an external data source, and items inside a synced folder can be copied out but not moved (409). Partial failures return 200 with a failed list.