polish: rebrand to Fleet Ops, add trilingual i18n, adaptive demo guide, and UX overhaul

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>

frontend/e2e/i18n-coverage.spec.ts

@@ -0,0 +1,73 @@
+import { expect, test } from "@playwright/test";
+import fs from "node:fs";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+
+// Pure Node-context checks (no browser needed): every locale must define exactly the
+// same set of translation keys. A missing key would otherwise silently fall back to
+// showing the raw key string in production -- this test makes that impossible to ship.
+
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+const LOCALES_DIR = path.resolve(__dirname, "../src/i18n/locales");
+const LANGUAGES = ["nl-BE", "en-GB", "fr-BE"];
+
+function collectKeyPaths(value: unknown, prefix = ""): string[] {
+  if (value === null || typeof value !== "object") {
+    return [prefix];
+  }
+  return Object.entries(value as Record<string, unknown>).flatMap(([key, nested]) =>
+    collectKeyPaths(nested, prefix ? `${prefix}.${key}` : key),
+  );
+}
+
+function loadNamespace(language: string, namespace: string): Record<string, unknown> {
+  const filePath = path.join(LOCALES_DIR, language, `${namespace}.json`);
+  return JSON.parse(fs.readFileSync(filePath, "utf-8"));
+}
+
+const namespaces = fs
+  .readdirSync(path.join(LOCALES_DIR, "nl-BE"))
+  .filter((f) => f.endsWith(".json"))
+  .map((f) => f.replace(/\.json$/, ""));
+
+test("every locale defines the same translation keys as nl-BE, for every namespace", () => {
+  expect(namespaces.length).toBeGreaterThan(0);
+
+  for (const namespace of namespaces) {
+    const referenceKeys = collectKeyPaths(loadNamespace("nl-BE", namespace)).sort();
+
+    for (const language of LANGUAGES) {
+      if (language === "nl-BE") continue;
+      const keys = collectKeyPaths(loadNamespace(language, namespace)).sort();
+      const missing = referenceKeys.filter((k) => !keys.includes(k));
+      const extra = keys.filter((k) => !referenceKeys.includes(k));
+
+      expect(
+        missing,
+        `${language}/${namespace}.json is missing keys present in nl-BE: ${missing.join(", ")}`,
+      ).toEqual([]);
+      expect(
+        extra,
+        `${language}/${namespace}.json has extra keys not present in nl-BE: ${extra.join(", ")}`,
+      ).toEqual([]);
+    }
+  }
+});
+
+test("no locale file contains an empty string value", () => {
+  for (const language of LANGUAGES) {
+    for (const namespace of namespaces) {
+      const data = loadNamespace(language, namespace);
+      const keys = collectKeyPaths(data);
+      for (const keyPath of keys) {
+        const value = keyPath.split(".").reduce<unknown>((acc, part) => {
+          if (acc && typeof acc === "object") return (acc as Record<string, unknown>)[part];
+          return undefined;
+        }, data);
+        if (typeof value === "string") {
+          expect(value.trim().length, `${language}/${namespace}.json:${keyPath} is empty`).toBeGreaterThan(0);
+        }
+      }
+    }
+  }
+});