Clean unused helpers after details-page simplification

- ScheduleDetailsPage: drop shiftYmd helper and selectedYmd local —
  both were left over from the removed day-sibling search path.
- ScheduleFlightBody.test: drop fireEvent import + FUTURE_340D /
  FUTURE_1H / YESTERDAY / todayUtc constants; they belonged to the
  Buy/Status button tests that moved to the summary-header layer.
- flight-details + error-handling integration tests: mock
  useCityName / useStationDisplayName so OnlineBoardDetailsPage can
  render without an ApiClientProvider wrapping — the station lookup
  hooks now transitively depend on useApiClient via the cached
  useDictionaries fetcher introduced in 7deb46a.

src/features/schedule/components/ScheduleDetailsPage.tsx

@@ -57,16 +57,6 @@ function formatApiDate(yyyymmdd: string): string {
   return `${yyyymmdd.slice(0, 4)}-${yyyymmdd.slice(4, 6)}-${yyyymmdd.slice(6, 8)}T00:00:00`;
 }
 
-/** Shift a yyyyMMdd date by `days` (negative for backwards). */
-function shiftYmd(yyyymmdd: string, days: number): string {
-  if (yyyymmdd.length !== 8) return yyyymmdd;
-  const d = new Date(
-    `${yyyymmdd.slice(0, 4)}-${yyyymmdd.slice(4, 6)}-${yyyymmdd.slice(6, 8)}T00:00:00`,
-  );
-  d.setDate(d.getDate() + days);
-  const pad = (n: number) => String(n).padStart(2, "0");
-  return `${d.getFullYear()}${pad(d.getMonth() + 1)}${pad(d.getDate())}`;
-}
 
 
 /**
@@ -113,13 +103,6 @@ export const ScheduleDetailsPage: FC<ScheduleDetailsPageProps> = ({
     return raw ? parseDetailsRequestParam(raw) : null;
   }, [searchParams]);
 
-  // TZ §4.1.16.2 — re-issue the parent schedule-route search so the
-  // left-side mini-list shows the available flight options for the
-  // selected day plus its neighbours. MUST be called unconditionally
-  // before any early returns to keep React's hook order stable.
-  //
-  const selectedYmd = flightIds[0]?.date ?? "";
-
   // Angular's `schedule-flights-mini-list` only shows a multi-day
   // accordion when `schedule.length > 1`; for a connecting itinerary
   // it renders a single card — the currently-open flight, with the

src/features/schedule/components/ScheduleFlightBody.test.tsx

@@ -12,7 +12,7 @@
  */
 
 import { describe, it, expect, vi } from "vitest";
-import { render, screen, fireEvent } from "@testing-library/react";
+import { render, screen } from "@testing-library/react";
 import type { ISimpleFlight, IFlightLeg } from "@/features/online-board/types.js";
 
 // ── i18n stub ─────────────────────────────────────────────────────────────────
@@ -161,25 +161,9 @@ function makeConnectingFlight(depUtc: string): ISimpleFlight {
 
 // ── Buy-gate helpers ──────────────────────────────────────────────────────────
 
-/** 10 days from now — buy should be visible */
+/** 10 days from now — used by the structure tests below to exercise a
+ *  future-dated flight against the leg-body renderer. */
 const FUTURE_10D = new Date(Date.now() + 10 * 24 * 3600 * 1000).toISOString();
-/** 340 days from now — buy should be hidden (> 330 days) */
-const FUTURE_340D = new Date(Date.now() + 340 * 24 * 3600 * 1000).toISOString();
-/** 1 hour from now — buy should be hidden (< 2h threshold) */
-const FUTURE_1H = new Date(Date.now() + 1 * 3600 * 1000).toISOString();
-/** Yesterday — buy should be hidden (past) */
-const YESTERDAY = new Date(Date.now() - 24 * 3600 * 1000).toISOString();
-/** Today (same calendar day) — status button should be visible */
-/** Return an ISO string that is guaranteed to be within today's UTC date.
- * Always use UTC noon (12:00) to avoid any local-to-UTC shift pushing us
- * into yesterday or tomorrow. */
-function todayUtc(): string {
-  const now = new Date();
-  // Force UTC noon of today — well within the UTC calendar day
-  return new Date(
-    Date.UTC(now.getUTCFullYear(), now.getUTCMonth(), now.getUTCDate(), 12, 0, 0),
-  ).toISOString();
-}
 
 // ── Tests ─────────────────────────────────────────────────────────────────────
 

tests/integration/online-board/error-handling.test.tsx

@@ -92,6 +92,13 @@ vi.mock("@/shared/hooks/useAppSettings.js", () => ({
   }),
 }));
 
+// OnlineBoardDetailsPage resolves station codes via useStationDisplayName,
+// which internally hits useApiClient — no ApiClientProvider in this tree.
+vi.mock("@/shared/hooks/useDictionaries.js", () => ({
+  useCityName: (code: string) => code,
+  useStationDisplayName: (code: string) => code,
+}));
+
 // ---------------------------------------------------------------------------
 // Constants
 // ---------------------------------------------------------------------------

tests/integration/online-board/flight-details.test.tsx

@@ -71,6 +71,14 @@ vi.mock("@/shared/hooks/useAppSettings.js", () => ({
   }),
 }));
 
+// OnlineBoardDetailsPage resolves station codes via useStationDisplayName,
+// which internally hits useApiClient. There's no ApiClientProvider in
+// this test tree, so stub the name-lookup hooks to echo the code.
+vi.mock("@/shared/hooks/useDictionaries.js", () => ({
+  useCityName: (code: string) => code,
+  useStationDisplayName: (code: string) => code,
+}));
+
 // ---------------------------------------------------------------------------
 // Helpers
 // ---------------------------------------------------------------------------