Add Bandcamp search and Listening Room page

Implement Bandcamp search service with autocomplete API and HTML
scraping fallback. Add /api/bandcamp/search and /api/bandcamp/embed
endpoints. Create Listening Room page with search, embedded player,
and queue management. Add navigation entry and Bandcamp link on
recommendation cards.

frontend/src/lib/api.ts

@@ -211,4 +211,30 @@ export const createBillingPortal = () =>
 export const getBillingStatus = () =>
   api.get<BillingStatusResponse>('/billing/status').then((r) => r.data)
 
+// Bandcamp
+export interface BandcampResult {
+  title: string
+  artist: string
+  art_url: string | null
+  bandcamp_url: string
+  item_type: string
+}
+
+export interface BandcampEmbed {
+  embed_url: string
+  title: string
+  artist: string
+  art_url: string | null
+}
+
+export async function searchBandcamp(query: string, type: string = 't'): Promise<BandcampResult[]> {
+  const { data } = await api.get('/bandcamp/search', { params: { q: query, type } })
+  return data
+}
+
+export async function getBandcampEmbed(url: string): Promise<BandcampEmbed> {
+  const { data } = await api.get('/bandcamp/embed', { params: { url } })
+  return data
+}
+
 export default api