Rotate touch 180 so BL and TR match screen labels.

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

src/touch.cpp

@@ -95,6 +95,10 @@ void touch_read_cb(lv_indev_t * /*indev*/, lv_indev_data_t *data) {
     y = SCREEN_HEIGHT - 1;
   }
 
+  // BL↔TR 对角反了：物理坐标整体旋转 180°
+  x = (int16_t)((SCREEN_WIDTH - 1) - x);
+  y = (int16_t)((SCREEN_HEIGHT - 1) - y);
+
   // LVGL 270 → UI
   g_dbg_phys_x = x;
   g_dbg_phys_y = y;