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/searchGroupOrder.ts

@@ -0,0 +1,77 @@
+// Persisted order of search result groups.
+//
+// Frontend-only preference, stored in localStorage per the `jellytau-view-mode`
+// precedent in library.ts — no Rust settings command backs this.
+//
+// TRACES: UR-050 | DR-066
+
+import { writable } from "svelte/store";
+import {
+  DEFAULT_GROUP_ORDER,
+  moveGroup,
+  normalizeGroupOrder,
+  reorderGroups,
+  type SearchGroupId,
+} from "$lib/utils/searchScope";
+
+const STORAGE_KEY = "jellytau-search-group-order";
+
+function load(): SearchGroupId[] {
+  if (typeof localStorage === "undefined") return [...DEFAULT_GROUP_ORDER];
+  try {
+    const raw = localStorage.getItem(STORAGE_KEY);
+    // A corrupt or hand-edited value must not break search rendering.
+    return normalizeGroupOrder(raw ? JSON.parse(raw) : null);
+  } catch {
+    return [...DEFAULT_GROUP_ORDER];
+  }
+}
+
+function persist(order: SearchGroupId[]) {
+  if (typeof localStorage === "undefined") return;
+  try {
+    localStorage.setItem(STORAGE_KEY, JSON.stringify(order));
+  } catch {
+    // Quota or private-mode failure — keep the in-memory order.
+  }
+}
+
+function createSearchGroupOrderStore() {
+  const { subscribe, set, update } = writable<SearchGroupId[]>(load());
+
+  return {
+    subscribe,
+
+    set(order: SearchGroupId[]) {
+      const normalized = normalizeGroupOrder(order);
+      persist(normalized);
+      set(normalized);
+    },
+
+    /** Move one group up (-1) or down (+1) — the keyboard-accessible path. */
+    move(id: SearchGroupId, delta: number) {
+      update((order) => {
+        const next = moveGroup(order, id, delta);
+        persist(next);
+        return next;
+      });
+    },
+
+    /** Drop handler for drag-and-drop reordering. */
+    reorder(from: number, to: number) {
+      update((order) => {
+        const next = reorderGroups(order, from, to);
+        persist(next);
+        return next;
+      });
+    },
+
+    reset() {
+      const next = [...DEFAULT_GROUP_ORDER];
+      persist(next);
+      set(next);
+    },
+  };
+}
+
+export const searchGroupOrder = createSearchGroupOrderStore();