Let the shell say where home is, and drop the router from the call

The call reached for react-router in five places to send the user
"home": on leaving without a lobby, from the lobby's recents link, from
the post-call screen, from the error page's return button and from the
header logo. Home is the standalone app's home page; the call has no
idea where that is, and a component has no such place at all — its host
decides what follows a call. Yet the component had to mount a
MemoryRouter just so those hooks would not throw.

`useLeaveToHome` is the way home as the shell supplies it: the app
provides `navigate("/")` from inside its router, the component provides
nothing, and everything that used to link to "/" now either calls it or,
when there is none, offers no way out. The logo becomes a plain logo,
the recents and "not now" links disappear, the error page's button does
too. `ClientProvider`'s logout goes the same way. The component no
longer renders a router.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

src/room/CallEndedView.tsx

@@ -9,8 +9,6 @@ import { type FC, type FormEventHandler, useCallback, useState } from "react";
 import { type MatrixClient } from "matrix-js-sdk";
 import { Trans, useTranslation } from "react-i18next";
 import { Button, Heading, Text } from "@vector-im/compound-web";
-import { useNavigate } from "react-router-dom";
-import { logger } from "matrix-js-sdk/lib/logger";
 
 import styles from "./CallEndedView.module.css";
 import feedbackStyle from "../input/FeedbackInput.module.css";
@@ -19,8 +17,9 @@ import { Header, HeaderLogo, LeftNav, RightNav } from "../Header";
 import { PosthogAnalytics } from "../analytics/PosthogAnalytics";
 import { FieldRow, InputField } from "../input/Input";
 import { StarRatingInput } from "../input/StarRatingInput";
-import { Link } from "../button/Link";
 import { LinkButton } from "../button";
+import { LeaveToHomeLink } from "../button/LeaveToHomeLink";
+import { useLeaveToHome } from "../LeaveToHomeContext";
 
 interface Props {
   client: MatrixClient;
@@ -38,7 +37,7 @@ export const CallEndedView: FC<Props> = ({
   endedCallId,
 }) => {
   const { t } = useTranslation();
-  const navigate = useNavigate();
+  const leaveToHome = useLeaveToHome();
 
   const { displayName } = useProfile(client);
   const [surveySubmitted, setSurveySubmitted] = useState(false);
@@ -68,14 +67,12 @@ export const CallEndedView: FC<Props> = ({
             setSurveySubmitted(true);
           } else if (!confineToRoom) {
             // if the user already has an account immediately go back to the home screen
-            navigate("/")?.catch((error) => {
-              logger.error("Failed to navigate to /", error);
-            });
+            leaveToHome?.();
           }
         }, 1000);
       }, 1000);
     },
-    [endedCallId, navigate, isPasswordlessUser, confineToRoom, starRating],
+    [endedCallId, leaveToHome, isPasswordlessUser, confineToRoom, starRating],
   );
 
   const createAccountDialog = isPasswordlessUser && (
@@ -87,6 +84,8 @@ export const CallEndedView: FC<Props> = ({
           calls
         </p>
       </Trans>
+      {/* Only guests of the standalone app are ever passwordless, so this
+      route is always the standalone app's own. */}
       <LinkButton className={styles.callEndedButton} to="/register">
         {t("call_ended_view.create_account_button")}
       </LinkButton>
@@ -157,7 +156,10 @@ export const CallEndedView: FC<Props> = ({
         </main>
         {!confineToRoom && (
           <Text className={styles.footer}>
-            <Link to="/"> {t("call_ended_view.not_now_button")} </Link>
+            <LeaveToHomeLink>
+              {" "}
+              {t("call_ended_view.not_now_button")}{" "}
+            </LeaveToHomeLink>
           </Text>
         )}
       </div>