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>

server/api/generate/music.post.ts

@@ -12,7 +12,8 @@ import {
   parseMusicEngine,
   parseMusicSeed,
   sanitizeMusicLyrics,
-  sanitizeMusicTags
+  sanitizeMusicTags,
+  yueLyricsProblem
 } from '~/utils/music'
 
 export default defineEventHandler(async (event) => {
@@ -62,6 +63,10 @@ export default defineEventHandler(async (event) => {
   const folderLocked = Boolean(destFolder?.protected && !destFolder.unlocked)
 
   const engine = parseMusicEngine(body.engine)
+  if (engine === 'yue' && !instrumental) {
+    const problem = yueLyricsProblem(lyrics)
+    if (problem) throw createError({ statusCode: 400, statusMessage: problem })
+  }
   const duration = clampMusicDuration(body.duration)
   const steps = clampMusicSteps(
     body.steps,