Working together on a page: merged changes, no silent overwrites

Merged, not overwritten. A save that meets a newer version merges your change into it: different paragraphs, list items or properties both stay. Only when you both changed the same lines does a banner ask, with Keep both, Use theirs or Use mine; their other changes stay either way.
Unsaved changes from earlier. Restore them merges your old unsaved changes into the page as it is now, instead of saving the old copy over newer edits.
Catching up. After your laptop sleeps, your connection drops or Markdrop restarts, an open page checks for changes made meanwhile, shows them, and saves what you typed offline.
Renamed, deleted, access changed. A page renamed while you have it open saves what you typed and moves to its new address (it used to stay on Saving…). A deleted page says so. Removed from a workspace, or made a viewer, your open pages check again at once.
Sub-pages and views. New, moved and deleted sub-pages show up under Pages inside on everyone's open copy. Two people changing a folder's saved views at once both keep their changes.
AI apps. update_document takes base_rev (the rev that get_document now returns), so an app can't overwrite a change made after it read the document. Every write tool takes an optional idempotency_key: a retry with the same key returns the first result instead of writing twice.