Map universal section-4 to Postamble outro and share AutoBand_StartOutro with ADC.

Exit piece mode before Postamble so universal chord loops can switch into the style outro stage once 3.bin has PostambleMIDI.

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

Global/Global.c

@@ -488,6 +488,29 @@ void Accomp_UpdatePlayingChord(void)
     AutoBandTop1_Note_On(midi_note_buff[i], 0x50);
 }
 
+/* 尾奏起奏：Postamble(0) + 同步起奏 + 当前和弦 Note_On。
+ * 供 ADC 独立尾奏键与万能模式第4段落键共用。
+ * 万能走 piece 循环，须先退出 piece，否则 Postamble 舞台切不过去；
+ * 尾奏 MIDI 须由音师写入 3.bin（见 Doc/音师需求_万能3.bin尾奏_20260914.md）。 */
+void AutoBand_StartOutro(void)
+{
+  uint8_t midi_note_buff[4] = {0,};
+  uint8_t note_cnt = 0;
+
+  /* 退出和弦走向 piece，再进风格尾奏舞台 */
+  AutoBandTop1_SetPiecePlayMode(0, 0, 0);
+  AutoBandTop1_Postamble(0);
+  /* 尾奏起奏前补发主音量，保证与图标一致 */
+  MasterVolume_Reapply();
+  AutoBandTop1_SyncStart();
+  wk_delay_ms(50);
+  note_cnt = GetChordNotesByType(KEY_ID_1629,chord_type_index_map[KEY_ID_1629].type,midi_note_buff);
+  for(uint8_t i = 0;i < note_cnt;i++)
+  {
+    AutoBandTop1_Note_On(midi_note_buff[i],0x50);
+  }
+}
+
 void ADC_IN1_KEY_Handle(uint8_t key,bool on)
 {
   uint8_t midi_note_buff[4] = {0,};
@@ -497,14 +520,20 @@ void ADC_IN1_KEY_Handle(uint8_t key,bool on)
   if(key_toggle[key] == 1)
   {
       //ResetAutoPowerCount();
+      if(key == 1)
+      {
+          /* 尾奏：与万能模式第4键共用同一起奏路径 */
+          AutoBand_StartOutro();
+      }
+      else
+      {
           switch(key)
           {
               case 3: AutoBandTop1_Preamble(0);  is_preamble = 1; break;
               case 0: AutoBandTop1_Preamble(1);  is_preamble = 1; break;
-          case 1: AutoBandTop1_Postamble(0); break;
               case 2: AutoBandTop1_Postamble(1); break;
           }
-      /* 前奏/尾奏起奏前补发主音量，保证与图标一致 */
+          /* 前奏/断奏起奏前补发主音量，保证与图标一致 */
           MasterVolume_Reapply();
           //AutoBandTop1_Start();
           AutoBandTop1_SyncStart();
@@ -521,6 +550,7 @@ void ADC_IN1_KEY_Handle(uint8_t key,bool on)
             AutoBandTop1_Note_On(midi_note_buff[i],0x50);
           }
       }
+  }
   else
   {  
       Stop_AutoBand();

Global/Global.h

@@ -214,6 +214,8 @@ void GUI_Item_AjustLoopValue(GUI_SWITCH * Group, int8_t Dir);
 
 void Send_volume(uint8_t vol);
 void MasterVolume_Reapply(void);
+/* 尾奏起奏：ADC 尾奏键与万能第4段落键共用 */
+void AutoBand_StartOutro(void);
 
 void ADC_IN1_KEY_Handle(uint8_t key,bool on);
 void TM1617_Handle(uint8_t key);

UI/UI_SongMode.c

@@ -237,6 +237,16 @@ void Touch_Action(int8_t FLAG, uint8_t ID, uint8_t areaIndex,uint8_t value)
     }
     else if(ID==GUI_PLAY_SECTION)
     {
+        /* 万能模式第4键：改为尾奏播放（与独立尾奏键同路径），不走 main4 */
+        if (mGuiData[GUI_TAB_INDEX].Current == 0 && value == 3)
+        {
+            last_value = mGuiData[ID].Current;
+            mGuiData[ID].Current = value;
+            AutoBand_StartOutro();
+            if (!UI_SetFocus(GUI_PLAY_SECTION))
+                Refresh_SectionSelect(last_value, &UI_Label[ID], &mGuiData[ID]);
+            return;
+        }
         if(mGuiData[ID].Current != value)
         {
           mGuiData[ID].Current = value;