Use existing i18n keys (INTERMEDIATE-LANDING-PLURAL-ONE, BACK-SCHEDULE) and drop non-existent fallbacks

src/features/online-board/components/TransferBar/TransferBar.test.tsx

@@ -97,11 +97,11 @@ describe("TransferBar", () => {
     expect(screen.getByTestId("transfer-bar")).toBeTruthy();
   });
 
-  it("renders SHARED.INTERMEDIATE-LANDING label and both times", () => {
+  it("renders SHARED.INTERMEDIATE-LANDING-PLURAL-ONE label and both times", () => {
     const leg = makeLeg({ arrLocal: "10:00", arrUtc: "2026-04-17T10:00:00Z" });
     const nextLeg = makeLeg({ depLocal: "11:30", depUtc: "2026-04-17T11:30:00Z" });
     render(<TransferBar leg={leg} nextLeg={nextLeg} viewType="Schedule" />);
-    expect(screen.getByText("SHARED.INTERMEDIATE-LANDING")).toBeTruthy();
+    expect(screen.getByText("SHARED.INTERMEDIATE-LANDING-PLURAL-ONE")).toBeTruthy();
     expect(screen.getByText("10:00")).toBeTruthy();
     expect(screen.getByText("11:30")).toBeTruthy();
   });

src/features/online-board/components/TransferBar/TransferBar.tsx

@@ -39,7 +39,7 @@ export const TransferBar: FC<TransferBarProps> = ({ leg, nextLeg, viewType }) =>
         </svg>
       </div>
       <div className="transfer-bar__content">
-        <span className="transfer-bar__type">{t("SHARED.INTERMEDIATE-LANDING")}</span>
+        <span className="transfer-bar__type">{t("SHARED.INTERMEDIATE-LANDING-PLURAL-ONE")}</span>
         <div className="transfer-bar__duration">
           <TransferTime
             arrivalUtc={leg.arrival.times.scheduledArrival.utc}

src/features/schedule/components/ScheduleDetailsPage.tsx

@@ -115,7 +115,7 @@ export const ScheduleDetailsPage: FC<ScheduleDetailsPageProps> = ({
       <span aria-hidden="true" className="schedule-details__back-arrow">
         {"\u2190"}
       </span>
-      {t("SHARED.BACK-SCHEDULE") || t("SHARED.BACK")}
+      {t("SHARED.BACK-SCHEDULE")}
     </Link>
   );
   const title = flightIds[0]

src/features/schedule/components/ScheduleFilter.tsx

@@ -258,7 +258,7 @@ export const ScheduleFilter: FC<ScheduleFilterProps> = ({
                 type="button"
                 className="schedule-filter__swap-btn"
                 onClick={handleSwap}
-                aria-label={t("SHARED.SWAP-CITIES") || "swap"}
+                aria-label="swap"
                 data-testid="swap-cities-button"
               >
                 <svg className="svg--change-city">