fix: translate remaining NL/FR interface gaps

Role names, audit/scenario labels, and status text were previously either
left in English or only partially translated:
- auth.json/demo.json role labels actually translated (not just labelled
  as translated): Operationsmanager/Verhuurmedewerker,
  Responsable des operations/Collaborateur de location.
- "Audit trail" -> Auditgeschiedenis/Piste d'audit (title, column header,
  and every mid-sentence occurrence across demo.json, quality.json,
  returns.json -- these embedded leaks were previously invisible to the
  whole-string identity check).
- "Open" (status) -> Openstaand, "Recent" -> Recentste,
  "Start scenario" -> Scenario starten / Demarrer le scenario.

Matching Playwright spec text updated in the same commit so the suite
never regresses through a broken intermediate state.

frontend/e2e/fleet-ops-correction.spec.ts

@@ -19,9 +19,9 @@ async function resetDemoData(request: APIRequestContext) {
 }
 
 const EXPLORE_OPS_MANAGER: Record<string, string> = {
-  "nl-BE": "Verken als Operations Manager",
+  "nl-BE": "Verken als Operationsmanager",
   "en-GB": "Explore as Operations Manager",
-  "fr-BE": "Explorer en tant qu'Operations Manager",
+  "fr-BE": "Explorer en tant que Responsable des opérations",
 };
 
 const REVIEW_RECOMMENDATION: Record<string, string> = {
@@ -74,6 +74,16 @@ test.describe("branding", () => {
   }
 });
 
+test("the Fleet Ops favicon is linked and resolves (not the browser's blank-tab default)", async ({ page, request }) => {
+  await resetDemoData(request);
+  await page.goto("/login");
+  const href = await page.locator('link[rel="icon"]').getAttribute("href");
+  expect(href).toBe("/favicon.svg");
+  const response = await page.request.get(href as string);
+  expect(response.ok()).toBeTruthy();
+  expect(response.headers()["content-type"]).toContain("svg");
+});
+
 test("language switcher control changes the UI and persists across a reload", async ({ page, request }) => {
   await resetDemoData(request);
   // Deliberately not using loginAsOpsManager here: its addInitScript would re-force