Replace the err instanceof ApiError ? err.message : t(fallback) anti-
pattern -- which showed raw English backend text for the common case and
only used the localized fallback for the rare network-failure case -- at
all 13 call sites across 7 files.
New frontend/src/api/errorMessages.ts (describeApiError) resolves a
caught error to a localized {title, explanation, nextStep?, technical}
by checking the 32 known AppError codes first, then known HTTP statuses
(401/403/404/409/422/500), then a fully generic fallback. New
ApiErrorNotice (PageChrome.tsx) renders title/explanation/nextStep with
the raw text demoted to a "Technical details"/"Details techniques"
disclosure -- never shown as the primary message.
ApiError itself is split out of client.ts into a standalone
api/apiError.ts with no import.meta.env dependency, so errorMessages.ts
(and its tests) can be loaded outside a Vite/browser context.
Rebrands the product from MobilityOps to Fleet Ops across the UI, backend defaults and
knowledge base, and makes nl-BE/en-GB/fr-BE full first-class languages: i18next with
eager-bundled per-namespace resources, a persisted accessible language switcher (topbar
and mobile drawer), locale-aware date/number formatting, and a coverage test that fails
the build on any missing or empty translation key.
Backend dynamic content (demo scenarios, blocked-reason text, integration status) moves
from fixed English/Dutch prose to stable message codes + params so the frontend can
localize it; the demo knowledge base gains a fully translated NL/EN/FR procedure corpus
(11 documents each) with per-language retrieval and localized evidence-state messages.
The Demo Guide becomes breakpoint-adaptive: a docked rail on extra-wide desktop, a
floating panel that auto-collapses to a persistent, closable progress chip on standard
desktop/tablet, and a collapsed/half/full bottom sheet on mobile -- with scroll+focus+
highlight on "go to this step", Escape handling, and reduced-motion support.
The Data Quality Workbench gets accessible choice-card decisions with a clear primary/
secondary/tertiary action hierarchy; the Automation ledger groups repeated successes and
uses meaningful short refs; the Audit trail groups events by correlation id with human
action labels and readable before/after diffs. Attention Queue, Today's movements,
Vehicles, Bookings and Data Quality rows are fully clickable (stretched-link pattern)
with independent secondary links, keyboard support and mobile touch targets.
Fixes a topbar overflow on mobile caused by the new language switcher (moved into the
mobile drawer at <=960px) and two dangling aria-labelledby references introduced this
session. Updates all affected Playwright specs for the new nl-BE default and the new
Audit/DemoGuide DOM structure, and adds new i18n-coverage, demo-guide-adaptive and
clickable-rows specs. 131 backend tests, Ruff and mypy, and 71 Playwright tests pass.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
NuklearRabbit