Drops the delta's starting point of every layer, keeping the rest of each entry.
🛑 Called when the store's content goes. A mark says "the store holds what the source held
up to here" — after a purge it holds nothing, and a delta from the old mark would bring back
only what changed since: a layer rebuilt from its latest edits, the rest missing, and nothing
to say so. Without a mark, the next pull is complete.
Never throws, like writePullState: the purge it follows must not be reported as failed.
Drops the delta's starting point of every layer, keeping the rest of each entry.
🛑 Called when the store's content goes. A mark says "the store holds what the source held up to here" — after a purge it holds nothing, and a delta from the old mark would bring back only what changed since: a layer rebuilt from its latest edits, the rest missing, and nothing to say so. Without a mark, the next pull is complete.
Never throws, like writePullState: the purge it follows must not be reported as failed.