fix(jellyfin): display playlist cover art

Uploaded playlist covers never showed in clients for two reasons: the
playlist BaseItemDto advertised no Primary ImageTag (so clients didn't
know to fetch a cover), and the public image endpoint resolved artwork
under the request's anonymous context, so a private playlist failed its
visibility filter and fell back to the placeholder. Advertise the Primary
image tag/blurhash on playlists, and resolve artwork under an elevated
context (as core/artwork's cache warmer does).

server/jellyfin/dto/mappers.go

@@ -191,6 +191,8 @@ func PlaylistToBaseItem(p model.Playlist) BaseItemDto {
 		MediaType:         "Audio",
 		ChildCount:        new(p.SongCount),
 		RunTimeTicks:      TicksFromSeconds(p.Duration),
+		ImageTags:         map[string]string{"Primary": p.ID},
+		ImageBlurHashes:   map[string]map[string]string{"Primary": {p.ID: blurHash(p.ID)}},
 		BackdropImageTags: []string{},
 	}
 }

server/jellyfin/dto/mappers_test.go

@@ -166,5 +166,8 @@ var _ = Describe("mappers", func() {
 		Expect(item.MediaType).To(Equal("Audio"))
 		Expect(*item.ChildCount).To(Equal(7))
 		Expect(item.RunTimeTicks).To(Equal(int64(1_200_000_000)))
+		Expect(item.ImageTags["Primary"]).To(Equal("pl-1"))
+		Expect(item.ImageBlurHashes["Primary"]).To(HaveKey("pl-1"))
+		Expect(item.ImageBlurHashes["Primary"]["pl-1"]).To(HaveLen(6))
 	})
 })

server/jellyfin/images.go

@@ -13,11 +13,16 @@ import (
 	"github.com/go-chi/chi/v5"
 	"github.com/navidrome/navidrome/log"
 	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/model/request"
 	"github.com/navidrome/navidrome/server/jellyfin/dto"
 )
 
 func (api *Router) getItemImage(w http.ResponseWriter, r *http.Request) {
-	ctx := r.Context()
+	// This endpoint is intentionally public (see routes), so the request carries no user. Artwork
+	// resolution for user-scoped items (private playlists) would otherwise fail its visibility
+	// filter and fall back to the placeholder, so resolve under an elevated context — the same
+	// approach core/artwork's cache warmer uses to pre-generate every item's cover.
+	ctx := request.WithUser(r.Context(), model.User{IsAdmin: true})
 	itemId := dto.DecodeID(chi.URLParam(r, "itemId"))
 	size, _ := strconv.Atoi(r.URL.Query().Get("maxWidth"))
 

server/jellyfin/images_test.go

@@ -13,6 +13,7 @@ import (
 	"github.com/go-chi/chi/v5"
 	"github.com/navidrome/navidrome/core/artwork"
 	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/model/request"
 	"github.com/navidrome/navidrome/server/jellyfin/dto"
 	"github.com/navidrome/navidrome/tests"
 	. "github.com/onsi/ginkgo/v2"
@@ -21,12 +22,14 @@ import (
 
 type fakeArtwork struct {
 	artwork.Artwork
-	recvId string
-	data   []byte
+	recvId  string
+	recvCtx context.Context
+	data    []byte
 }
 
 func (f *fakeArtwork) GetOrPlaceholder(ctx context.Context, id string, size int, square bool) (io.ReadCloser, time.Time, error) {
 	f.recvId = id
+	f.recvCtx = ctx
 	data := f.data
 	if data == nil {
 		data = []byte("IMG")
@@ -86,6 +89,24 @@ var _ = Describe("Images", func() {
 		Expect(w.Code).To(Equal(http.StatusOK))
 		Expect(fa.recvId).To(ContainSubstring("pl1"))
 	})
+
+	// This endpoint is public (no user in the request), so artwork must be resolved under an
+	// elevated context; otherwise a private playlist's cover fails its visibility filter and
+	// silently falls back to the placeholder.
+	It("resolves artwork under an elevated admin context", func() {
+		ds := &tests.MockDataStore{}
+		ds.Album(context.Background()).(*tests.MockAlbumRepo).SetData(model.Albums{{ID: "a1", Name: "One"}})
+		fa := &fakeArtwork{}
+		api := &Router{ds: ds, artwork: fa}
+
+		w, r := newImageRequest(dto.EncodeID("a1"))
+		api.getItemImage(w, r)
+
+		Expect(w.Code).To(Equal(http.StatusOK))
+		u, ok := request.UserFrom(fa.recvCtx)
+		Expect(ok).To(BeTrue())
+		Expect(u.IsAdmin).To(BeTrue())
+	})
 })
 
 var _ = Describe("postItemImage", func() {