Dragging a LAN or decky, or resizing a NetBox, updates React state
but previously vanished on reload because the grid-layout adapter
rewrote everything from the graph. Add a per-topology localStorage
snapshot (key: mazenet.layout.<topologyId>) that captures net
x/y/w/h and decky x/y; useLayoutPersistor writes it debounced, and
getTopology merges it over adaptTopology's grid so entities without
a stored entry still fall back to a clean auto-layout. Deleting a
topology calls clearLayout to drop its snapshot.
anti
167582b887