fix(lyrics): prefer workers.dev LyricsPlus mirror first

Trim the LyricsPlus server list to the workers.dev and binimum mirrors
and update tests to match the new primary endpoint order.

go_backend/lyrics_lyricsplus.go

@@ -24,12 +24,8 @@ import (
 // Public LyricsPlus / KPOE servers (mirrors). Tried in order with failover.
 // Sourced from the upstream YouLy+ client server list.
 var lyricsPlusServers = []string{
-	"https://lyricsplus.binimum.org",
-	"https://lyricsplus.prjktla.my.id",
-	"https://lyricsplus.atomix.one",
 	"https://lyricsplus.prjktla.workers.dev",
-	"https://lyricsplus-seven.vercel.app",
-	"https://lyrics-plus-backend.vercel.app",
+	"https://lyricsplus.binimum.org",
 }
 
 type LyricsPlusClient struct {

go_backend/lyrics_supplement_test.go

@@ -251,7 +251,7 @@ func TestConcurrentLyricsProvidersPreferEarlierProviderWithinGrace(t *testing.T)
 func TestExternalLyricsProvidersWithFakeHTTP(t *testing.T) {
 	clearAppleMusicToken()
 	defer clearAppleMusicToken()
-	if len(lyricsPlusServers) == 0 || lyricsPlusServers[0] != "https://lyricsplus.binimum.org" {
+	if len(lyricsPlusServers) == 0 || lyricsPlusServers[0] != "https://lyricsplus.prjktla.workers.dev" {
 		t.Fatalf("unexpected LyricsPlus server order = %#v", lyricsPlusServers)
 	}