feat(search): context-scoped search with filter chips and group order

Add a search scope (all/music/shows/movies) resolved from the entry
route and adjustable via filter chips, threaded through the library
store's search() into includeItemTypes. Results group by type in a
user-configurable order, editable from settings.

TRACES: UR-049 | DR-063, DR-064, DR-065; UR-050 | DR-066, DR-067

src/lib/stores/library.ts

@@ -4,6 +4,8 @@
 import { writable, derived } from "svelte/store";
 import { listen, type UnlistenFn } from "@tauri-apps/api/event";
 import type { Library, MediaItem, SearchResult, Genre } from "$lib/api/types";
+import type { SearchOptions } from "$lib/api/bindings";
+import { scopeItemTypes, type SearchScope } from "$lib/utils/searchScope";
 import { auth } from "./auth";
 
 /**
@@ -222,7 +224,17 @@ function createLibraryStore() {
     }
   }
 
-  async function search(query: string) {
+  /**
+   * Search the library, optionally narrowed to a scope.
+   *
+   * `scope` is additive and defaults to `all`, which sends no
+   * `includeItemTypes` at all — see scopeItemTypes() for why that differs from
+   * listing every type. Both the online and offline repository paths already
+   * honour the filter.
+   *
+   * TRACES: UR-049 | DR-065
+   */
+  async function search(query: string, scope: SearchScope = "all") {
     // Bump the request id for every call (including clears) so any in-flight
     // backend update for a previous query is ignored when it arrives.
     const requestId = ++searchRequestId;
@@ -247,8 +259,13 @@ function createLibraryStore() {
       // Phase 1: the command resolves with instant local-cache results. The
       // merged (cache + server) union arrives later via the `search-event`
       // listener above, tagged with this same requestId.
+      const itemTypes = scopeItemTypes(scope);
+      const options: SearchOptions = { limit: 10000 };
+      // Omit the key entirely for the `all` scope rather than sending null.
+      if (itemTypes) options.includeItemTypes = itemTypes;
+
       const result = await Promise.race([
-        repo.search(query, { limit: 10000 }, requestId),
+        repo.search(query, options, requestId),
         timeoutPromise
       ]);