feat(web/m7-352): Playlist type gains kind/system_variant/seed_artist_id fields

web/src/lib/api/types.ts

@@ -58,6 +58,9 @@ export type Playlist = {
   name: string;
   description: string;
   is_public: boolean;
+  kind: 'user' | 'system';
+  system_variant: 'for_you' | 'songs_like_artist' | null;
+  seed_artist_id: string | null;
   cover_url: string;        // empty string when no cover; UI renders glyph
   track_count: number;
   duration_sec: number;

web/src/lib/components/AddToPlaylistMenu.test.ts

@@ -12,6 +12,9 @@ const playlistsData = vi.hoisted(() => ({
       name: 'B-list',
       description: '',
       is_public: false,
+      kind: 'user',
+      system_variant: null,
+      seed_artist_id: null,
       cover_url: '',
       track_count: 3,
       duration_sec: 0,
@@ -25,6 +28,9 @@ const playlistsData = vi.hoisted(() => ({
       name: 'A-list',
       description: '',
       is_public: false,
+      kind: 'user',
+      system_variant: null,
+      seed_artist_id: null,
       cover_url: '',
       track_count: 5,
       duration_sec: 0,
@@ -58,6 +64,9 @@ vi.mock('$lib/api/playlists', () => ({
     name: 'New',
     description: '',
     is_public: false,
+    kind: 'user',
+    system_variant: null,
+    seed_artist_id: null,
     cover_url: '',
     track_count: 0,
     duration_sec: 0,

web/src/lib/components/PlaylistCard.test.ts

@@ -16,6 +16,9 @@ const base: Playlist = {
   name: 'Saturday morning',
   description: '',
   is_public: false,
+  kind: 'user',
+  system_variant: null,
+  seed_artist_id: null,
   cover_url: '',
   track_count: 12,
   duration_sec: 0,