Replace SD card storage with on-board Flash filesystem (FFat), allocating 9MB internal storage partition for keepsakes

sound_picture_app/Audio_Player.cpp

@@ -1,5 +1,6 @@
 #include "Audio_Player.h"
 #include "Audio.h"
+#include "FFat.h"
 
 static Audio audio;
 static TaskHandle_t audioTaskHandle = NULL;
@@ -27,7 +28,7 @@ void initAudioPlayer() {
 // ── Public controls ───────────────────────────────────────────────────────────
 void playAudio(const char* fullPath) {
   printf("Audio: playing %s\r\n", fullPath);
-  audio.connecttoFS(SD_MMC, fullPath);
+  audio.connecttoFS(FFat, fullPath);
 }
 
 void playMemoryAudio(int memoryIndex) {