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.

backend/app/api/endpoints/bandcamp.py

@@ -0,0 +1,58 @@
+from fastapi import APIRouter, Depends, HTTPException, Query
+from pydantic import BaseModel
+
+from app.core.security import get_current_user
+from app.models.user import User
+from app.services.bandcamp import search_bandcamp, get_embed_data
+
+router = APIRouter(prefix="/bandcamp", tags=["bandcamp"])
+
+
+class BandcampResult(BaseModel):
+    title: str
+    artist: str
+    art_url: str | None = None
+    bandcamp_url: str
+    item_type: str
+
+
+class BandcampEmbedResponse(BaseModel):
+    embed_url: str
+    title: str
+    artist: str
+    art_url: str | None = None
+
+
+@router.get("/search", response_model=list[BandcampResult])
+async def bandcamp_search(
+    q: str = Query(..., min_length=1),
+    type: str = Query("t", pattern="^[tab]$"),
+    user: User = Depends(get_current_user),
+):
+    """Search Bandcamp for tracks, albums, or artists."""
+    results = await search_bandcamp(q.strip(), item_type=type)
+    return [BandcampResult(**r) for r in results]
+
+
+@router.get("/embed", response_model=BandcampEmbedResponse)
+async def bandcamp_embed(
+    url: str = Query(..., min_length=1),
+    user: User = Depends(get_current_user),
+):
+    """Get embed data for a Bandcamp URL."""
+    if "bandcamp.com" not in url:
+        raise HTTPException(status_code=400, detail="Not a valid Bandcamp URL")
+
+    data = await get_embed_data(url.strip())
+    if not data:
+        raise HTTPException(
+            status_code=404,
+            detail="Could not extract embed data from this Bandcamp page",
+        )
+
+    return BandcampEmbedResponse(
+        embed_url=data["embed_url"],
+        title=data["title"],
+        artist=data["artist"],
+        art_url=data.get("art_url"),
+    )