feat(web): add API client modules for Lidarr, requests, admin

T13 of the M5a Lidarr plan. Three new client modules wrap api.get/post/put/del
helpers and the existing TanStack Query qk namespace:

  lidarr.ts   - searchLidarr() + createLidarrSearchQuery()
  requests.ts - createRequest, listMyRequests, getRequest, cancelRequest;
                createMyRequestsQuery(); cancel goes through apiFetch
                directly because the backend returns the cancelled row body
                (api.del's return type is fixed to null).
  admin.ts    - getLidarrConfig, putLidarrConfig, testLidarrConnection,
                listQualityProfiles, listRootFolders, listAdminRequests,
                approveRequest, rejectRequest; query factories for each
                read; quality profiles + root folders take an enabled prop
                so the call site decides when Lidarr is configured.

Shared LidarrRequestStatus / LidarrRequestKind enums and request/config/
search-result shapes added to types.ts. Per-module helpers (CreateRequestParams)
stay in their module files. testLidarrConnection returns a discriminated union
({ok:true,version} | {ok:false,error}) and never throws on ok:false so the
SPA can render either branch.

qk extended with lidarrSearch, myRequests, lidarrConfig,
lidarrQualityProfiles, lidarrRootFolders, adminRequests.

Tests mirror likes.test.ts (vi.mock('./client')) and cover URL construction,
query-param encoding, body shapes, the not-ok testLidarrConnection branch,
and qk additions. 32 new tests, 217 total passing.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

web/src/lib/api/requests.ts

@@ -0,0 +1,67 @@
+import { createQuery } from '@tanstack/svelte-query';
+import { api, apiFetch } from './client';
+import { qk } from './queries';
+import type { LidarrRequest, LidarrRequestKind } from './types';
+
+// CreateRequestParams is the shape callers pass; unused MBID fields are
+// optional, and we omit them from the wire body rather than sending empty
+// strings (the backend tolerates either, but this keeps test expectations
+// crisp and matches the spec §5 wire shape).
+export type CreateRequestParams = {
+  kind: LidarrRequestKind;
+  lidarr_artist_mbid: string;
+  lidarr_album_mbid?: string;
+  lidarr_track_mbid?: string;
+  artist_name: string;
+  album_title?: string;
+  track_title?: string;
+};
+
+type CreateRequestBody = {
+  kind: LidarrRequestKind;
+  lidarr_artist_mbid: string;
+  artist_name: string;
+  lidarr_album_mbid?: string;
+  lidarr_track_mbid?: string;
+  album_title?: string;
+  track_title?: string;
+};
+
+function buildCreateBody(params: CreateRequestParams): CreateRequestBody {
+  const body: CreateRequestBody = {
+    kind: params.kind,
+    lidarr_artist_mbid: params.lidarr_artist_mbid,
+    artist_name: params.artist_name
+  };
+  if (params.lidarr_album_mbid)  body.lidarr_album_mbid  = params.lidarr_album_mbid;
+  if (params.lidarr_track_mbid)  body.lidarr_track_mbid  = params.lidarr_track_mbid;
+  if (params.album_title)        body.album_title        = params.album_title;
+  if (params.track_title)        body.track_title        = params.track_title;
+  return body;
+}
+
+export async function createRequest(params: CreateRequestParams): Promise<LidarrRequest> {
+  return api.post<LidarrRequest>('/api/requests', buildCreateBody(params));
+}
+
+export async function listMyRequests(): Promise<LidarrRequest[]> {
+  return api.get<LidarrRequest[]>('/api/requests');
+}
+
+export async function getRequest(id: string): Promise<LidarrRequest> {
+  return api.get<LidarrRequest>(`/api/requests/${id}`);
+}
+
+// Server returns the cancelled row body (not 204) so callers can patch the
+// cache without a refetch. api.del's return type is fixed to null, so we
+// drop down to apiFetch here to keep typing honest.
+export async function cancelRequest(id: string): Promise<LidarrRequest> {
+  return apiFetch(`/api/requests/${id}`, { method: 'DELETE' }) as Promise<LidarrRequest>;
+}
+
+export function createMyRequestsQuery() {
+  return createQuery({
+    queryKey: qk.myRequests(),
+    queryFn: listMyRequests
+  });
+}