fix: LittleFS partition label mismatch and display rotation (180°)

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

partitions_custom.csv

@@ -3,5 +3,5 @@ nvs,        data, nvs,      0x9000,    0x5000,
 otadata,    data, ota,      0xe000,    0x2000,
 app0,       app,  ota_0,    0x10000,   0x680000,
 app1,       app,  ota_1,    0x690000,  0x680000,
-littlefs,   data, spiffs,   0xD10000,  0x80000,
+spiffs,     data, spiffs,   0xD10000,  0x80000,
 coredump,   data, coredump, 0xD90000,  0x10000,

src/display_manager.cpp

@@ -17,8 +17,7 @@ void DisplayManager::begin(PowerManager& power) {
     _display = &M5.Display;
 
     // Set rotation for landscape (device physically rotated)
-    // Rotation value depends on how the display is mounted — likely 1 or 3
-    _display->setRotation(1);
+    _display->setRotation(3);
 
     Serial.printf("[display] Initialized: %dx%d, rotation=%d\n",
                   _display->width(), _display->height(), _display->getRotation());