Adds a "Sidebar navigation" section to Settings -> Appearance, above the
existing profile-menu customizer, with the same drag-to-reorder + switch UI.
- New sidebarNav preference: one { id, pinned } entry per navigable row
(projects, hub, images, train, video, recipes, export), array order = render
order. Defaults match the shipped layout, so an untouched install is unchanged.
- Unpinning moves a row into the More flyout rather than hiding it, so no page
becomes unreachable. New chat and Search stay fixed as actions.
- app-sidebar now renders from one navRows descriptor map, so a pinned row and
its flyout counterpart cannot drift; the More row appears only when something
is unpinned and highlights off whatever it actually holds.
- Mirrored in the backend PersonalizationCustomization: without it the model's
extra="ignore" would drop the field, and because sync replaces local state
with the server's copy once customization is saved, the user's pin order would
reset on the next sync. The validator dedupes and back-fills like sidebarMenu
but preserves the client's order, since here order is meaningful.
Frontend typecheck, i18n parity and catalog checks pass; 32 personalization
tests pass, including a round-trip asserting a reordered list survives a save.