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.

TactilityC/Source/tt_hal_display.cpp

@@ -20,7 +20,7 @@ static ColorFormat toColorFormat(tt::hal::display::ColorFormat format) {
         case tt::hal::display::ColorFormat::RGB888:
             return COLOR_FORMAT_RGB888;
         default:
-            tt_crash("ColorFormat not supported");
+            check(false, "ColorFormat not supported");
     }
 }