fix(free): preserve expert chord/transpose across mode switch

NavBar no longer forces I after stop; remember context before leave and prefer saved fret chord on no-fret pick.

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

Global/Global.c

@@ -105,7 +105,7 @@ int16_t MIC_VOL_MAP[11]= {-9000,-7000,-5000,-3000,-1000,1000,3000,5000,7000,9000
 
 uint8_t TOUCH_AREA_NUM = (sizeof(Touch_Areas)/sizeof(Touch_AreaTypeDef));
 
-const uint8_t Version[3] = {0,2,25}; /* major.minor.patch — 0.2.25: 普通无指板拨片沿用专业最后指板和弦 */
+const uint8_t Version[3] = {0,2,27}; /* major.minor.patch — 0.2.27: 切模式前记专业移调/指板；无指板拨片优先用记忆 */
 uint8_t Led = 8;
 bool PressFlag = 0;
 
@@ -648,9 +648,9 @@ void Accomp_ApplyDefaultIChord(void)
 }
 
 /* 专业/普通共用：最后一次指板和弦（供普通无指板拨片）。
- * 另记专业停键时的移调：0xFF=尚未在专业停过；移调合法值 0~11。
+ * 另记专业侧移调：0xFF=尚未记下；移调合法值 0~11。
  * chord: 0=无记录；1~21=指板键。 */
-static uint8_t s_expert_stop_transpose = 0xFFu;
+static uint8_t s_saved_transpose = 0xFFu;
 static uint8_t s_last_fret_chord = 0;
 
 static void Accomp_RememberLastFretChord(uint8_t key)
@@ -659,14 +659,20 @@ static void Accomp_RememberLastFretChord(uint8_t key)
     s_last_fret_chord = key;
 }
 
-static void Expert_RememberStopContext(void)
+static void Accomp_RememberTranspose(void)
+{
+  s_saved_transpose = (uint8_t)mGuiData[GUI_TRANSPOSE].Current;
+}
+
+/* 停键或切模式前：按当前页记住和弦；专业再记移调 */
+void Accomp_RememberPlayContext(void)
 {
   uint8_t tab = (uint8_t)mGuiData[GUI_TAB_INDEX].Current;
   uint8_t last = (uint8_t)mGuiData[GUI_TAB_LAST_INDEX].Current;
 
   if (tab == 1 || (tab == 3 && last == 1))
   {
-    s_expert_stop_transpose = (uint8_t)mGuiData[GUI_TRANSPOSE].Current;
+    Accomp_RememberTranspose();
     Accomp_RememberLastFretChord(KEY_ID_1629);
   }
   else if (tab == 2 || (tab == 3 && last == 2))
@@ -675,28 +681,35 @@ static void Expert_RememberStopContext(void)
   }
 }
 
-/* 普通无指板拨片：移调用专业停键值；和弦用专业/普通记下的最后指板，否则一级 */
+static void Expert_RememberStopContext(void)
+{
+  Accomp_RememberPlayContext();
+}
+
+/* 普通无指板拨片：优先用记下的最后指板和弦（勿信切模式后的默认 KEY=一级）；
+ * 移调用专业侧记下的值；都没有才退回一级。 */
 static void FreeMode_ApplyLastFretChordForNoFretPick(void)
 {
-  if (s_expert_stop_transpose != 0xFFu &&
+  if (s_saved_transpose != 0xFFu &&
-      (uint8_t)mGuiData[GUI_TRANSPOSE].Current != s_expert_stop_transpose)
+      (uint8_t)mGuiData[GUI_TRANSPOSE].Current != s_saved_transpose)
   {
-    mGuiData[GUI_TRANSPOSE].Current = s_expert_stop_transpose;
+    mGuiData[GUI_TRANSPOSE].Current = s_saved_transpose;
     UITask_Sendmsg(MSG_ID_BLE_UI_REFRESH, GUI_TRANSPOSE, 0, 0);
   }
 
-  if (KEY_ID_1629 >= 1u && KEY_ID_1629 <= 21u)
+  /* 切模式 NavBar 会把 KEY 打成一级，必须以记忆为准 */
-  {
-    Accomp_RememberLastFretChord(KEY_ID_1629);
-    PressFlag = 0;
-    return;
-  }
   if (s_last_fret_chord >= 1u && s_last_fret_chord <= 21u)
   {
     KEY_ID_1629 = s_last_fret_chord;
     PressFlag = 0;
     return;
   }
+  if (KEY_ID_1629 >= 1u && KEY_ID_1629 <= 21u)
+  {
+    Accomp_RememberLastFretChord(KEY_ID_1629);
+    PressFlag = 0;
+    return;
+  }
   Accomp_ApplyDefaultIChord();
 }
 
@@ -1482,12 +1495,16 @@ void TM1629_Handle(uint8_t key)
         }
         uint8_t group = (key - 1) / 3;          /* 1~3→0, 4~6→1, ..., 19~21→6 */
         KEY_ID_1629 = key;
-        /* 专业/普通（及对应设置页）：记下最后指板和弦，供普通无指板拨片沿用 */
+        /* 专业/普通（及对应设置页）：记下最后指板和弦；专业同时记移调 */
         {
           uint8_t tab = (uint8_t)mGuiData[GUI_TAB_INDEX].Current;
           uint8_t last = (uint8_t)mGuiData[GUI_TAB_LAST_INDEX].Current;
-          if (tab == 1 || tab == 2 ||
+          if (tab == 1 || (tab == 3 && last == 1))
-              (tab == 3 && (last == 1 || last == 2)))
+          {
+            Accomp_RememberTranspose();
+            Accomp_RememberLastFretChord(key);
+          }
+          else if (tab == 2 || (tab == 3 && last == 2))
             Accomp_RememberLastFretChord(key);
         }
         MIDI        = (STRING_MIDI *)Chord_Midi_Table[group];
@@ -1610,7 +1627,7 @@ void Pick_Handle()
   }
 
   /* 左手未触发和弦板（或落在拍速/停止键）时：拨片默认发当前调一级大和弦伴奏。
-   * 普通无指板也可起奏：用专业最后指板和弦（如 VI），无记录才退回一级；无操作则偶拍停。 */
+   * 普通无指板也可起奏：用专业/普通记下的最后指板和弦，无记录才退回一级；无操作则偶拍停。 */
   {
   uint8_t free_pick_no_fret =
       (mGuiData[GUI_TAB_INDEX].Current == 2 &&
@@ -1618,7 +1635,7 @@ void Pick_Handle()
 
   if (free_pick_no_fret)
   {
-    FreeMode_ApplyExpertChordForNoFretPick();
+    FreeMode_ApplyLastFretChordForNoFretPick();
     chord_id = KEY_ID_1629;
   }
   else if (mGuiData[GUI_TAB_INDEX].Current != 2 &&

Global/Global.h

@@ -257,6 +257,8 @@ void BL_Set_led(uint8_t Led, uint8_t chord_type);
 uint8_t GetChordNotesByType(uint8_t MIDI_Index,uint8_t type,uint8_t *buff);
 /* 伴奏已在播时仅更新和弦音，不 Restart（快转调） */
 void Accomp_UpdatePlayingChord(void);
+/* 切模式/停键前记住专业移调与最后指板和弦 */
+void Accomp_RememberPlayContext(void);
 /* 段落键等主动刷新伴奏活动，避免 PlayTick 短暂停滞被判为已停 */
 void Band_NotifyPlayActivity(void);
 void BT_Chord_offset_map(uint8_t pos_offset,uint8_t chord_offset);

UI/UI_SongMode.c

@@ -303,6 +303,8 @@ void Touch_Action(int8_t FLAG, uint8_t ID, uint8_t areaIndex,uint8_t value)
     {
         if(mGuiData[ID].Current != value)
         {
+            /* 改 TAB 前先记住当前专业/普通指板与移调 */
+            Accomp_RememberPlayContext();
             mGuiData[ID].Current = value;
 
             app_tm1629_all_on(LED_COLOR_G);

UI/UI_global.c

@@ -1049,15 +1049,15 @@ void UI_NavBar_Action(uint8_t value)
 {
 	/* 离开万能后 LOOP_LIGHT 停更，须显式恢复全绿（旧 GUI_TAB_INDEX 路径曾做） */
 	app_tm1629_all_on(LED_COLOR_G);
-	/* 底栏切模式/进设置：立即结束当前伴奏（设置页不走 ReloadTonePreset） */
+	/* 先记住当前专业/普通的指板与移调，再停；勿再强制一级（会盖掉记忆供普通无指板拨片） */
+	Accomp_RememberPlayContext();
 	Stop_AutoBand();
-	/* 切模式后拨片/前奏默认当前调一级 */
-	Accomp_ApplyDefaultIChord();
 
 	switch (value)
 	{
 		case UI0902_NAV_UNIVERSAL:
 			/* Init 内会设 TAB 并 ReloadTonePreset，勿在此前加载（会仍用旧 TAB） */
+			Accomp_ApplyDefaultIChord(); /* 万能拨片默认一级 */
 			MenuPage_SongMode_Proc();
 			break;
 		case UI0902_NAV_NORMAL: