Fix congrats screen not refreshing (#3594)

ts/routes/congrats/CongratsPage.svelte

@@ -4,6 +4,7 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
 -->
 <script lang="ts">
     import type { CongratsInfoResponse } from "@generated/anki/scheduler_pb";
+    import { congratsInfo } from "@generated/backend";
     import * as tr from "@generated/ftl";
     import { bridgeLink } from "@tslib/bridgecommand";
 
@@ -11,8 +12,10 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
     import Container from "$lib/components/Container.svelte";
 
     import { buildNextLearnMsg } from "./lib";
+    import { onMount } from "svelte";
 
     export let info: CongratsInfoResponse;
+    export let refreshPeriodically = true;
 
     const congrats = tr.schedulingCongratulationsFinished();
     let nextLearnMsg: string;
@@ -26,6 +29,18 @@ License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
     const customStudyMsg = tr.schedulingHowToCustomStudy({
         customStudy,
     });
+
+    onMount(() => {
+        if (refreshPeriodically) {
+            setInterval(async () => {
+                try {
+                    info = await congratsInfo({});
+                } catch {
+                    console.log("congrats fetch failed");
+                }
+            }, 60000);
+        }
+    });
 </script>
 
 <Container --gutter-block="1rem" --gutter-inline="2px" breakpoint="sm">

ts/routes/congrats/index.ts

@@ -20,21 +20,9 @@ export async function setupCongrats(): Promise<CongratsPage> {
     const page = new CongratsPage({
         // use #congrats if it exists, otherwise entire body
         target: customMountPoint ?? document.body,
-        props: { info },
+        props: { info, refreshPeriodically: !customMountPoint },
     });
 
-    // refresh automatically if a custom area not provided
-    if (!customMountPoint) {
-        setInterval(async () => {
-            try {
-                const info = await congratsInfo({});
-                page.$set({ info });
-            } catch {
-                console.log("congrats fetch failed");
-            }
-        }, 60000);
-    }
-
     return page;
 }