music(chord): 修抓取 mode 传错 + 自动抓取 role 与展示对齐

startChordFetch 把内部 state key 'chord' 直接当 API mode 发给后端，
后端只认 letters/functional → '抓取失败'。改用 CHORD_API_MODE='functional'。

连带：自动抓取存的 role 'chord_functional' 与前端展示 + 手动上传用的
'chord' 不一致，抓成功也不显示。chord_mode_to_role 默认分支改回 'chord'。

apps/music/frontend/src/views/PlayerView.vue

@@ -587,6 +587,8 @@ async function runInspire() {
 }
 
 // chord —— 单 mode（只抓 yopu 默认数字级数版）
+// 'chord' 是内部 state key / tab 名；发给后端 API 的 mode 必须是 'functional'（数字级数版）
+const CHORD_API_MODE = 'functional'
 const chordStates = ref({ chord: 'idle' })
 const chordErrors = ref({ chord: '' })
 const chordPollTimers = { chord: null }
@@ -989,7 +991,7 @@ async function startChordFetch(mode) {
   chordStates.value = { ...chordStates.value, [mode]: 'pending' }
   chordErrors.value = { ...chordErrors.value, [mode]: '' }
   try {
-    const r = await chordFetch(selectedId.value, mode)
+    const r = await chordFetch(selectedId.value, CHORD_API_MODE)
     if (r.status === 'completed') {
       await reloadPiece()
       chordStates.value = { ...chordStates.value, [mode]: 'completed' }
@@ -1014,7 +1016,7 @@ async function pollChord(mode) {
     return
   }
   try {
-    const r = await chordStatus(selectedId.value, mode)
+    const r = await chordStatus(selectedId.value, CHORD_API_MODE)
     chordStates.value = { ...chordStates.value, [mode]: r.status || 'pending' }
     chordErrors.value = { ...chordErrors.value, [mode]: r.error || '' }
     if (r.status === 'completed') {

apps/music/src/main.rs

@@ -1397,7 +1397,8 @@ struct ChordModeQuery {
 fn chord_mode_to_role(mode: &str) -> &'static str {
     match mode {
         "letters" => "chord_letters",
-        _ => "chord_functional",
+        // 单 mode 简化后，数字级数版统一用 role 'chord'，与手动上传 + 前端展示一致
+        _ => "chord",
     }
 }