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/usbsettings/UsbSettings.cpp

@@ -11,12 +11,12 @@
 
 namespace tt::app::usbsettings {
 
-static void onRebootMassStorageSdmmc(TT_UNUSED lv_event_t* event) {
+static void onRebootMassStorageSdmmc(lv_event_t* event) {
     hal::usb::rebootIntoMassStorageSdmmc();
 }
 
 // Flash reboot handler
-static void onRebootMassStorageFlash(TT_UNUSED lv_event_t* event) {
+static void onRebootMassStorageFlash(lv_event_t* event) {
     hal::usb::rebootIntoMassStorageFlash();
 }