fix(home): $effect-Loop bei sort=viewed via untrack

Der Profile-Switch-Refetch-Effect las allLoading in der sync tracking-
Phase. Der await fetch beendete die Sync-Phase, das finale
allLoading = false im finally lief ausserhalb → wurde als externer
Write interpretiert → Effect rerun → naechster Fetch → Endlosschleife.

2136 GETs auf /api/recipes/all?sort=viewed in 8s beobachtet.

Fix: nur profileStore.active bleibt tracked (der tatsaechliche
Trigger). allSort/allLoading werden in untrack() gelesen — die Writes
auf allLoading im finally triggern damit keinen Effect-Rerun mehr.

Verifiziert lokal: 1 Request statt 2000+ bei mount mit allSort=viewed.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/routes/+page.svelte

@@ -1,5 +1,5 @@
 <script lang="ts">
-  import { onMount, tick } from 'svelte';
+  import { onMount, tick, untrack } from 'svelte';
   import { page } from '$app/stores';
   import { CookingPot, X, ChevronDown } from 'lucide-svelte';
   import { slide } from 'svelte/transition';
@@ -235,27 +235,31 @@
   // profiles, refetch with the new profile_id so the list reflects what
   // the *current* profile has viewed. Other sorts are profile-agnostic
   // and don't need this.
+  //
+  // Only `profileStore.active` must be a tracked dep. `allSort` /
+  // `allLoading` are read inside untrack: otherwise the `allLoading = false`
+  // write in the fetch-finally would re-trigger the effect and start the
+  // next fetch → endless loop.
   $effect(() => {
-    const active = profileStore.active;
-    if (allSort !== 'viewed') return;
-    if (allLoading) return;
-    // Re-fetch the first page; rehydrate would re-load the previous
-    // depth, but a sort-context change should reset to page 1 anyway.
-    void (async () => {
-      allLoading = true;
-      try {
-        const res = await fetch(buildAllUrl('viewed', ALL_PAGE, 0));
-        if (!res.ok) return;
-        const body = await res.json();
-        const hits = body.hits as SearchHit[];
-        allRecipes = hits;
-        allExhausted = hits.length < ALL_PAGE;
-      } finally {
-        allLoading = false;
-      }
-      // 'active' is referenced so $effect tracks it as a dep:
-      void active;
-    })();
+    // eslint-disable-next-line @typescript-eslint/no-unused-expressions
+    profileStore.active;
+    untrack(() => {
+      if (allSort !== 'viewed') return;
+      if (allLoading) return;
+      void (async () => {
+        allLoading = true;
+        try {
+          const res = await fetch(buildAllUrl('viewed', ALL_PAGE, 0));
+          if (!res.ok) return;
+          const body = await res.json();
+          const hits = body.hits as SearchHit[];
+          allRecipes = hits;
+          allExhausted = hits.length < ALL_PAGE;
+        } finally {
+          allLoading = false;
+        }
+      })();
+    });
   });
 
   // Sync current query back into the URL as ?q=... via replaceState,