Use '/sd' instead of '/sdcard' for accessing the sd card

it's cleaner

lua/settings.lua

@@ -319,7 +319,7 @@ local ThemeSettings = SettingsScreen:new {
     local theme_dir_iter = filesystem.iterator("/.themes/")
     for dir in theme_dir_iter do
       local theme_name = tostring(dir):match("(.+).lua$")
-      themeOptions[theme_name] = "/sdcard/.themes/" .. theme_name .. ".lua"
+      themeOptions[theme_name] = "/sd/.themes/" .. theme_name .. ".lua"
     end
 
     local saved_theme = theme.theme_filename();

src/drivers/storage.cpp

@@ -31,7 +31,7 @@ static const uint8_t kMaxOpenFiles = 8;
 
 namespace drivers {
 
-const char* kStoragePath = "/sdcard";
+const char* kStoragePath = "/sd";
 
 auto SdStorage::Create(IGpios& gpio) -> cpp::result<SdStorage*, Error> {
   gpio.WriteSync(IGpios::Pin::kSdPowerEnable, 1);

src/tangara/ui/screenshot.cpp

@@ -34,7 +34,7 @@ auto SaveScreenshot(lv_obj_t* obj, const std::string& path) -> void {
   }
 
   // The LVGL lodepng fork uses LVGL's file API, so an extra '/' is needed.
-  std::string fullpath = "//sdcard/" + path;
+  std::string fullpath = "//sd/" + path;
 
   auto res = lodepng_encode_file(fullpath.c_str(), buf->data, buf->header.w,
                                  buf->header.h, LCT_RGB, 8);

src/tangara/ui/ui_fsm.cpp

@@ -730,7 +730,7 @@ void Lua::entry() {
     sPowerFastChargeEnabled.setDirect(sServices->nvs().FastCharge());
 
     if (sServices->sd() == drivers::SdState::kMounted) {
-      sLua->RunScript("/sdcard/config.lua");
+      sLua->RunScript("/sd/config.lua");
     }
     sLua->RunScript("/lua/main.lua");
   }