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/lib/stores/home.ts

@@ -1,5 +1,5 @@
 // Home screen data store - featured items, continue watching, recently added
-// TRACES: UR-023, UR-024, UR-034, UR-059 | DR-026, DR-027, DR-038, DR-039, DR-089
+// TRACES: UR-023, UR-024, UR-034, UR-059, UR-067 | DR-026, DR-027, DR-038, DR-039, DR-089, DR-118
 import { writable, derived } from "svelte/store";
 import type { MediaItem } from "$lib/api/types";
 import { auth } from "./auth";
@@ -12,6 +12,10 @@ interface HomeState {
   latestItems: MediaItem[];
   recentlyPlayedAudio: MediaItem[];
   resumeMovies: MediaItem[];
+  /** Favourites per scope. Empty rows are not rendered. TRACES: UR-067 | DR-118 */
+  favoriteMovies: MediaItem[];
+  favoriteShows: MediaItem[];
+  favoriteMusic: MediaItem[];
   isLoading: boolean;
   error: string | null;
 }
@@ -24,6 +28,9 @@ function createHomeStore() {
     latestItems: [],
     recentlyPlayedAudio: [],
     resumeMovies: [],
+    favoriteMovies: [],
+    favoriteShows: [],
+    favoriteMusic: [],
     isLoading: false,
     error: null,
   };
@@ -46,6 +53,11 @@ function createHomeStore() {
         repo.getLatestItems("", 16),
         repo.getRecentlyPlayedAudio(12), // Backend now handles intelligent grouping
         repo.getResumeMovies(12),
+        // Favourites, one request per row. The scope is opaque — Rust decides
+        // which item types it covers. TRACES: UR-067 | DR-118
+        repo.getFavorites("movies", { limit: 20 }),
+        repo.getFavorites("tv", { limit: 20 }),
+        repo.getFavorites("music", { limit: 20 }),
       ]);
 
       const valueOr = <T>(i: number, fallback: T): T =>
@@ -60,6 +72,10 @@ function createHomeStore() {
       const latest = valueOr(2, [] as typeof initialState.latestItems);
       const recentAudio = valueOr(3, [] as typeof initialState.recentlyPlayedAudio);
       const resumeMovies = valueOr(4, [] as typeof initialState.resumeMovies);
+      const emptyResult = { items: [] as MediaItem[], totalRecordCount: 0 };
+      const favoriteMovies = valueOr(5, emptyResult).items;
+      const favoriteShows = valueOr(6, emptyResult).items;
+      const favoriteMusic = valueOr(7, emptyResult).items;
 
       // Use resume items or latest as hero items
       const hero = resume.length >= 3 ? resume.slice(0, 5) : latest.slice(0, 5);
@@ -72,6 +88,9 @@ function createHomeStore() {
         latestItems: latest,
         recentlyPlayedAudio: recentAudio,
         resumeMovies: resumeMovies,
+        favoriteMovies,
+        favoriteShows,
+        favoriteMusic,
         isLoading: false,
       }));
     } catch (error) {
@@ -101,4 +120,7 @@ export const nextUpItems = derived(home, $home => $home.nextUpItems);
 export const latestItems = derived(home, $home => $home.latestItems);
 export const recentlyPlayedAudio = derived(home, $home => $home.recentlyPlayedAudio);
 export const resumeMovies = derived(home, $home => $home.resumeMovies);
+export const favoriteMovies = derived(home, $home => $home.favoriteMovies);
+export const favoriteShows = derived(home, $home => $home.favoriteShows);
+export const favoriteMusic = derived(home, $home => $home.favoriteMusic);
 export const isHomeLoading = derived(home, $home => $home.isLoading);