Tighten YuE lyrics validation and Comfy music workflow wiring.

Require section tags before queueing YuE and keep the ACE/YuE path changes that were already in progress.

Co-authored-by: Cursor <cursoragent@cursor.com>

utils/music.ts

@@ -94,6 +94,22 @@ export function sanitizeMusicLyrics(raw: unknown, instrumental = false) {
   return String(raw || '').replace(/\r\n/g, '\n').trim().slice(0, MUSIC_LYRICS_MAX)
 }
 
+/** YuE splits on [Section] headers. Returns how many sections are present. */
+export function countYueLyricSections(lyrics: unknown) {
+  const text = String(lyrics || '')
+  const matches = text.match(/\[[^\]]+\]/g)
+  return matches ? matches.length : 0
+}
+
+export function yueLyricsProblem(lyrics: unknown): string | null {
+  const text = String(lyrics || '').trim()
+  if (!text) return 'YuE needs lyrics with section tags like [Verse 1] and [Chorus].'
+  if (countYueLyricSections(text) < 1) {
+    return 'YuE lyrics must include at least one [Section] tag (use the chips under Lyrics).'
+  }
+  return null
+}
+
 export function parseMusicSeed(raw: unknown) {
   const text = String(raw ?? '').trim().toLowerCase()
   if (!text || text === 'random') return Math.floor(Math.random() * 2_147_483_647)