Various improvements (#461)

* **New Features**
  * Time and delay utilities added (ticks, ms, µs); SD card now uses an expansion-header CS pin; HTTP downloads warn when run on the GUI task and yield to avoid blocking.

* **Bug Fixes / Reliability**
  * Many hard-crash paths converted to guarded checks to reduce abrupt termination and improve stability.

* **Tests**
  * Unit tests added to validate time and delay accuracy.

* **Chores**
  * License header and build/macro updates.

Tactility/Source/app/gpssettings/GpsSettings.cpp

@@ -318,7 +318,7 @@ class GpsSettingsApp final : public App {
         }
     }
 
-    void onGpsToggled(TT_UNUSED lv_event_t* event) {
+    void onGpsToggled(lv_event_t* event) {
         bool wants_on = lv_obj_has_state(switchWidget, LV_STATE_CHECKED);
         auto state = service->getState();
         bool is_on = (state == service::gps::State::On) || (state == service::gps::State::OnPending);