improve lastfm playlist parity and fallback resolution

Queue resolved last.fm tracks as playlist media to preserve playlist semantics, and add a robust mirror-based parser fallback for last.fm temporary unavailable responses while keeping track order and duplicates.

cmd/rip/main_test.go

@@ -166,3 +166,41 @@ func TestNormalizeCodecRejectsUnknown(t *testing.T) {
 		t.Fatalf("expected error for unsupported codec")
 	}
 }
+
+func TestGroupLastFMResolvedTracksBySourcePreservesOrderAndDuplicates(t *testing.T) {
+	resolved := []resolvedLastFMTrack{
+		{Source: "tidal", ID: "1"},
+		{Source: "tidal", ID: "1"},
+		{Source: "qobuz", ID: "2"},
+		{Source: "tidal", ID: "3"},
+		{Source: "", ID: "4"},
+	}
+	groups := groupLastFMResolvedTracksBySource(resolved)
+	if len(groups["tidal"]) != 3 {
+		t.Fatalf("tidal ids len = %d, want 3", len(groups["tidal"]))
+	}
+	if len(groups["qobuz"]) != 1 {
+		t.Fatalf("qobuz ids len = %d, want 1", len(groups["qobuz"]))
+	}
+	if groups["tidal"][0] != "1" || groups["tidal"][1] != "1" || groups["tidal"][2] != "3" {
+		t.Fatalf("unexpected tidal ordering: %+v", groups["tidal"])
+	}
+}
+
+func TestExtractLastFMTracksFromMirrorMarkdown(t *testing.T) {
+	md := `Title: My Playlist | user playlists | Last.fm
+| Play | Image | Loved | Name | Artist name | Buy | Options | Duration |
+| --- | --- | --- | --- | --- | --- | --- | --- |
+| [Play track](https://x) | [img](https://i) | x | [Song A](https://a) | [Artist A](https://aa) | | | 3:00 |
+| [Play track](https://x) | [img](https://i) | x | [Song B](https://b) | [Artist B](https://bb) | | | 4:00 |`
+	title, tracks := extractLastFMTracksFromMirrorMarkdown(md)
+	if title != "My Playlist" {
+		t.Fatalf("title = %q, want %q", title, "My Playlist")
+	}
+	if len(tracks) != 2 {
+		t.Fatalf("tracks len = %d, want 2", len(tracks))
+	}
+	if tracks[0].Title != "Song A" || tracks[0].Artist != "Artist A" {
+		t.Fatalf("unexpected first track: %+v", tracks[0])
+	}
+}