feat(search): answer search from a local index; tier downloads by lifetime

Search's instant leg read only downloaded items, so with no downloads it
returned nothing and every keystroke fell through to a full Recursive=true
server query. It now reads the whole synced catalog through the same
availability CTE get_items uses, gated on the same include_catalog_browse
flag so search and browse cannot diverge. (UR-065, DR-108)

Also fixes three defects found while confirming that:

- items_fts grew by a full duplicate index every catalog pass. INSERT OR
  REPLACE fires no AFTER DELETE trigger without recursive_triggers, so the
  old index row was orphaned, and a TEXT PRIMARY KEY meant the replacement
  took a fresh rowid and inserted a second entry. Now a real upsert, with
  migration 021 rebuilding existing indexes. (DR-110)
- DELETE FROM items existed nowhere, so server-side deletions never
  propagated. Adds a post-crawl mark-and-sweep, scoped to crawled types,
  skipping downloaded items, and refusing to run after a partial crawl
  because items.parent_id cascades. (DR-110)
- The index omitted MusicArtist, Playlist and People, which search groups
  results by. Adds them plus people_fts (migration 022). (DR-111)

Re-indexing moves from a frontend startup call to a Rust background task
with a 6h TTL, so a long session no longer searches a stale catalog and a
restart no longer forces a crawl regardless of freshness. (DR-109, IR-030)

Downloads gain a lifetime tier. Eviction selected every completed row by
age with no download_source filter, so hitting the storage limit deleted
the oldest download -- typically one saved deliberately for offline -- to
make room for a precached track. It now reclaims only 'auto' rows, and
expired ones are reclaimed first, before live cache is evicted.
(DR-126, DR-127)

Downloaded video and audio-only handoffs now play from disk instead of
streaming; the video path had never consulted downloads at all. No
transcode is involved: MPV runs video=no and ExoPlayer has no surface for
an Audio item. (DR-123 in part, DR-128)

FTS queries are built as quoted phrases so apostrophes, hyphens and
slashes are data rather than operator syntax, and the item-type filter is
bound rather than interpolated.

Specs: docs/specs/catalog-index-search.md,
docs/specs/read-through-media-cache.md

Includes concurrently-developed favourites browsing and background-audio
stream-end handling; the two workstreams share offline.rs, lib.rs and
online.rs, so no subset of files builds independently.

src/routes/library/+page.svelte

@@ -201,6 +201,20 @@
     <div>
       <div class="flex items-center justify-between mb-6">
         <h1 class="text-2xl font-bold text-white">Your Libraries</h1>
+        <div class="flex items-center gap-1">
+        <!-- Favourites cut across libraries, so they live beside the library
+             list rather than inside one. ux-flows §5C.2.
+             TRACES: UR-067 | DR-117 -->
+        <button
+          onclick={() => goto('/library/favorites')}
+          class="p-2 rounded-lg hover:bg-white/10 transition-colors text-gray-400 hover:text-white"
+          title="Favourites"
+          aria-label="Favourites"
+        >
+          <svg class="w-6 h-6" fill="none" stroke="currentColor" viewBox="0 0 24 24" stroke-width="2">
+            <path stroke-linecap="round" stroke-linejoin="round" d="M4.318 6.318a4.5 4.5 0 000 6.364L12 20.364l7.682-7.682a4.5 4.5 0 00-6.364-6.364L12 7.636l-1.318-1.318a4.5 4.5 0 00-6.364 0z" />
+          </svg>
+        </button>
         <button
           onclick={() => goto('/settings')}
           class="p-2 rounded-lg hover:bg-white/10 transition-colors text-gray-400 hover:text-white"
@@ -211,6 +225,7 @@
             <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M15 12a3 3 0 11-6 0 3 3 0 016 0z" />
           </svg>
         </button>
+        </div>
       </div>
 
       {#if $isLibraryLoading}

src/routes/library/[id]/+page.svelte

@@ -19,6 +19,8 @@
   import SeriesDownloadButton from "$lib/components/library/SeriesDownloadButton.svelte";
   import ClearHistoryButton from "$lib/components/library/ClearHistoryButton.svelte";
   import VideoDownloadButton from "$lib/components/library/VideoDownloadButton.svelte";
+  import FavoriteButton from "$lib/components/FavoriteButton.svelte";
+  import { favoriteOverrides, resolveIsFavorite } from "$lib/stores/favorites";
   import CastSection from "$lib/components/library/CastSection.svelte";
   import PersonDetailView from "$lib/components/library/PersonDetailView.svelte";
   import RelatedItemsSection from "$lib/components/library/RelatedItemsSection.svelte";
@@ -557,6 +559,14 @@
                 size="lg"
               />
             {/if}
+            <!-- Favourite. Sits with Play/Download rather than in the header,
+                 per ux-flows §5B.3/§5B.4. TRACES: UR-068 | DR-119 -->
+            <FavoriteButton
+              itemId={item.id}
+              isFavorite={resolveIsFavorite(item, $favoriteOverrides)}
+              size="lg"
+              className="self-center"
+            />
           </div>
 
           <!-- Overview -->

src/routes/library/favorites/+page.svelte

@@ -0,0 +1,144 @@
+<!--
+  Favourites — everything the viewer has hearted, across every library.
+
+  Scope tabs are `?scope=`, so a tab is linkable and survives a back press (the
+  same convention as the video library `?view=` tabs). Each tab sends an opaque
+  `SearchScope`; what it *means* in Jellyfin item types is expanded in Rust
+  (`SearchScope::item_types`), never here — see docs/specs/scoped-search-boundary.md.
+
+  ux-flows §5C.2. TRACES: UR-067 | DR-117
+-->
+<script lang="ts">
+  import { onMount, onDestroy } from "svelte";
+  import { page } from "$app/stores";
+  import { goto } from "$app/navigation";
+  import { listen, type UnlistenFn } from "@tauri-apps/api/event";
+  import { auth } from "$lib/stores/auth";
+  import { isServerReachable } from "$lib/stores/connectivity";
+  import { useServerReachabilityReload } from "$lib/composables/useServerReachabilityReload";
+  import { navigateBack } from "$lib/utils/navigation";
+  import { favoriteOverrides, retainFavorites } from "$lib/stores/favorites";
+  import LibraryGrid from "$lib/components/library/LibraryGrid.svelte";
+  import BackButton from "$lib/components/common/BackButton.svelte";
+  import type { MediaItem, Library } from "$lib/api/types";
+  import {
+    FAVORITE_SCOPES,
+    FAVORITE_SCOPE_LABELS,
+    resolveFavoritesScope,
+    favoritesRouteUrl,
+    emptyStateMessage,
+  } from "$lib/utils/favoritesView";
+
+  const scope = $derived(resolveFavoritesScope($page.url.searchParams.get("scope")));
+
+  let items = $state<MediaItem[]>([]);
+  let loading = $state(true);
+  let loadError = $state<string | null>(null);
+  let unlistenFavorites: UnlistenFn | null = null;
+
+  // Un-hearting here must remove the card immediately rather than wait for a
+  // refetch; a newly hearted item stays put. TRACES: UR-067 | DR-117 | UT-106
+  const visibleItems = $derived(retainFavorites(items, $favoriteOverrides));
+
+  async function load(currentScope = scope) {
+    loading = true;
+    loadError = null;
+    try {
+      const repo = auth.getRepository();
+      const result = await repo.getFavorites(currentScope, { limit: 500 });
+      items = result.items;
+    } catch (error) {
+      console.error("Failed to load favorites:", error);
+      loadError = "Could not load your favourites.";
+      items = [];
+    } finally {
+      loading = false;
+      markLoaded();
+    }
+  }
+
+  // Reload when the tab changes.
+  let loadedScope = "";
+  $effect(() => {
+    if (scope === loadedScope) return;
+    loadedScope = scope;
+    load(scope);
+  });
+
+  onMount(async () => {
+    // The backend reports ids whose favourite state changed behind our back —
+    // a favourite marked in another client, or pending toggles pushed on
+    // reconnect. Refetch rather than patch: the scope decides what belongs.
+    // TRACES: UR-069 | DR-120
+    unlistenFavorites = await listen("favorites-changed", () => {
+      load(scope);
+    });
+  });
+
+  onDestroy(() => {
+    unlistenFavorites?.();
+    unlistenFavorites = null;
+  });
+
+  const { markLoaded } = useServerReachabilityReload(() => load(scope));
+
+  function selectScope(next: (typeof FAVORITE_SCOPES)[number]) {
+    if (next === scope) return;
+    // replaceState: switching tabs is not a back-press-worthy navigation step.
+    goto(favoritesRouteUrl(next), { replaceState: true, noScroll: true });
+  }
+
+  function handleItemClick(item: MediaItem | Library) {
+    goto(`/library/${item.id}`);
+  }
+</script>
+
+<div class="space-y-4">
+  <div class="flex items-center gap-3 px-4 pt-4">
+    <BackButton onClick={() => navigateBack("/library")} />
+    <h1 class="text-2xl font-bold text-white">Favourites</h1>
+  </div>
+
+  <nav class="flex items-center gap-1 px-4" aria-label="Favourite categories">
+    {#each FAVORITE_SCOPES as tab (tab)}
+      <button
+        onclick={() => selectScope(tab)}
+        aria-current={tab === scope ? "page" : undefined}
+        class="px-4 py-2 rounded-lg text-sm font-medium transition-colors
+               {tab === scope
+                 ? 'bg-[var(--color-jellyfin)] text-white'
+                 : 'text-gray-400 hover:text-white hover:bg-white/10'}"
+      >
+        {FAVORITE_SCOPE_LABELS[tab]}
+      </button>
+    {/each}
+  </nav>
+
+  <div class="px-4 pb-8">
+    {#if loading}
+      <div class="grid grid-cols-2 md:grid-cols-4 lg:grid-cols-6 gap-4">
+        {#each Array(12) as _}
+          <div class="animate-pulse">
+            <div class="aspect-square bg-[var(--color-surface)] rounded-lg mb-2"></div>
+            <div class="h-4 bg-[var(--color-surface)] rounded w-3/4"></div>
+          </div>
+        {/each}
+      </div>
+    {:else if loadError}
+      <p class="text-gray-400 py-12 text-center">{loadError}</p>
+    {:else if visibleItems.length === 0}
+      <div class="py-16 text-center space-y-2">
+        <p class="text-gray-300">{emptyStateMessage(scope)}</p>
+        {#if !$isServerReachable}
+          <p class="text-sm text-gray-500">
+            Offline — showing favourites available on this device.
+          </p>
+        {/if}
+      </div>
+    {:else}
+      <!-- Card shape follows the media, not the page (§5A.1), so a mixed All
+           tab reads as posters, squares and thumbnails side by side. -->
+      <LibraryGrid items={visibleItems} onItemClick={handleItemClick} />
+    {/if}
+  </div>
+</div>