Add ACE-Step music generation to the studio and library.

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

server/api/library/tracks/[id]/audio.get.ts

@@ -0,0 +1,19 @@
+import { existsSync } from 'node:fs'
+import { sendPathWithRange } from '~/server/utils/httpRange'
+import { musicContentType } from '~/utils/music'
+
+export default defineEventHandler((event) => {
+  const { owner } = assertLibraryOwner(event)
+  const id = String(getRouterParam(event, 'id') || '')
+  const track = getTrack(owner, id)
+  assertFolderAccess(event, track.folderId)
+  const path = trackAudioPath(owner, track.id, track.ext)
+  if (!existsSync(path)) {
+    throw createError({ statusCode: 404, statusMessage: 'Audio file is missing' })
+  }
+  const ext = track.ext || 'flac'
+  return sendPathWithRange(event, path, musicContentType(ext), {
+    'Content-Disposition': `inline; filename="${safeDownloadName(track.name)}.${ext}"`,
+    'Cache-Control': 'private, max-age=0, must-revalidate'
+  })
+})