Schema foundation for the B2 dashboard batch, mirroring the navItems shape:
- `overviewMobile: UiLayoutItem[]` — a separate single-column (id+visible)
ordering for phones, kept fully disjoint from the desktop 2D `overviewBlocks`
grid so mobile ordering never pollutes grid coords.
- `topbarItems: UiLayoutItem[]` — show/hide list for toggleable top-bar
elements (status badge, theme toggle, kiosk button); essential elements stay
pinned in the consumer.
Server `normalizeLayout` round-trips both (idOr + dedup, total over corrupt
input); defaults seed first run. `LayoutContext` exposes them with
setOverviewMobile/setTopbarItems setters and reconcile-on-consume semantics, so
adding a widget/element later just appears. Old configs lacking the fields fall
back to defaults on load.
Consumers (mobile render, topbar render + config, drag-sort panel) land in
follow-up B2 commits.
DrSmoothl
45d651614b