feat: X3 gyroscope-based tilt page turning via QMI8658 IMU (#1636)

Co-authored-by: justinian <juicecutlus@gmail.com>
Co-authored-by: Vincent Politzer <vincent@skipwithjoy.com>

src/CrossPointSettings.h

@@ -137,6 +137,8 @@ class CrossPointSettings {
   // Image rendering in EPUB reader
   enum IMAGE_RENDERING { IMAGES_DISPLAY = 0, IMAGES_PLACEHOLDER = 1, IMAGES_SUPPRESS = 2, IMAGE_RENDERING_COUNT };
 
+  enum TILT_PAGE_TURN { TILT_OFF = 0, TILT_NORMAL = 1, TILT_NVERTED = 2, TILT_PAGE_TURN_COUNT };
+
   // Sleep screen settings
   uint8_t sleepScreen = DARK;
   // Sleep screen cover mode settings
@@ -199,6 +201,8 @@ class CrossPointSettings {
   uint8_t showHiddenFiles = 0;
   // Image rendering mode in EPUB reader
   uint8_t imageRendering = IMAGES_DISPLAY;
+  // Tilt-based page turning (X3 only — requires QMI8658 IMU)
+  uint8_t tiltPageTurn = TILT_OFF;
 
   ~CrossPointSettings() = default;