`n.toLocaleString()` groups in the BROWSER's locale, so an English UI in a
Hungarian browser printed "1 234 567" while a Hungarian UI in an English
browser printed "1,234,567" — the number half of the date defect fixed in
618ef812. One `formatNumber` in lib/format.ts (a per-language cached
Intl.NumberFormat, like the relative-time formatters beside it) now serves
every grouped figure: Stats, Scheduler, the channel columns and the stats
popover, VideoCard's view tooltip, the ItemCount pill, and formatTotalHours.
ReleaseNotes' `toLocaleDateString(undefined, …)` was the one DATE site the
previous sweep missed; it moves onto formatDate.
The new cases assert both languages and that the two differ, instead of
comparing against the runtime's own default: that default is Hungarian on the
dev box and English on a CI image, so a one-language assertion would pass
under the old bug on half the machines. Verified in Chromium on :5173 with the
browser forced to hu-HU and the UI in English — Stats, Scheduler and the
channel table all keep comma grouping.
The app HAS a platform layer -- AnchoredPopover (22 importers, with
arrows/typeahead/Escape/anchor-flip), QueryState (21), Modal (17),
PageShell, DataTable, Tabs, Tooltip and ~26 more -- but it sat flat among
~160 feature components with nothing marking it as one. Several of those
files describe themselves as 'the one place' or 'canonical' and were
still bypassed by hand-rolled markup, because a layer nobody can see is a
layer nobody uses; three separate inventory passes of this codebase
misread it the same way.
Moves the 33 domain-free modules into components/ui/, rewrites the
imports in 89 files, and makes the boundary a lint rule rather than a
convention: inside ui/ a one-level-up import (a feature component) and
any lib/api slice are errors. The rule was verified to fire on both and
to leave generic lib/ helpers alone. README.md states which side of the
line a component belongs on and why.
No behaviour change: 3x tsc, eslint, knip, prettier and 687 vitest tests
all green; no backend file touched.