The Settings page's instant score-ring toggle PUT the full dashboard
layout, built from the client's cached `remote` snapshot. That snapshot
can go stale mid-flight: if a normal tile/chart Save committed a newer
layout first, the ring request's explicit stale `widgets` (and
`comparisonBaseline` / `chartOverlayPrefs`) still won on write and
silently reverted the just-saved layout whenever it resolved last.
The ring mutation now PUTs only the two ring fields
(`buildRingMutationPayload`). `widgets` joins the existing
preserve-when-absent merge (`LAYOUT_FIELD_MERGE_DISPOSITION`) so an
omitted field is carried forward from whatever is currently stored
instead of a client-held copy, closing the race regardless of request
order.
Marc-André Bombeck
8736f44442