feat(mangas): per-field sort options + direction toggle on the catalog (0.88.0)

Sort the manga catalog by created / updated / title / author with an
independent asc/desc direction control. An omitted `order` defaults per field
(dates newest-first, text A→Z), matching the UI, so a bare `?sort=<field>`
means the same thing in the browser and over the API; `sort=recent` remains a
back-compat alias for `created`.

- Backend: SortField/SortOrder parsed with validation (structured 422 on bad
  input), per-field default_order, NULLS LAST only on the nullable author key,
  and migration 0033 indexing mangas(updated_at DESC, id) to back the default
  sort and its id tie-break.
- Frontend: catalog sort field + direction (SegmentedControl) on desktop and a
  mobile bottom sheet; pure helpers in $lib/mangaSort; keyboard-accessible
  direction control; visible Direction labels and a sheet "Done" button.
- Tests: backend integration coverage (defaults, alias, invalid input,
  ascending-id tie-break), frontend unit + e2e.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/src/lib/api/mangas.ts

@@ -1,7 +1,8 @@
 import { request, type Manga, type MangaStatus, type Page } from './client';
 import type { ContentWarning } from './page_tags';
 
-export type MangaSort = 'recent' | 'title';
+export type MangaSort = 'created' | 'updated' | 'title' | 'author';
+export type SortOrder = 'asc' | 'desc';
 
 export type AuthorRef = { id: string; name: string };
 export type GenreRef = { id: string; name: string };
@@ -39,6 +40,7 @@ export type ListOptions = {
     limit?: number;
     offset?: number;
     sort?: MangaSort;
+    order?: SortOrder;
 };
 
 export type MangasPage = {
@@ -68,6 +70,7 @@ export async function listMangas(opts: ListOptions = {}): Promise<MangasPage> {
     if (opts.limit != null) params.set('limit', String(opts.limit));
     if (opts.offset != null) params.set('offset', String(opts.offset));
     if (opts.sort) params.set('sort', opts.sort);
+    if (opts.order) params.set('order', opts.order);
     const qs = params.toString();
     return request<MangasPage>(`/v1/mangas${qs ? `?${qs}` : ''}`);
 }