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.

Devices/simulator/Source/hal/SdlDisplay.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include "SdlTouch.h"
+#include <Tactility/Check.h>
 #include <Tactility/hal/display/DisplayDevice.h>
 
 /** Hack: variable comes from LvglTask.cpp */
@@ -14,11 +15,11 @@ public:
     std::string getDescription() const override { return ""; }
 
     bool start() override { return true; }
-    bool stop() override { tt_crash("Not supported"); }
+    bool stop() override { check(false, "Not supported"); }
 
     bool supportsLvgl() const override { return true; }
     bool startLvgl() override { return displayHandle != nullptr; }
-    bool stopLvgl() override { tt_crash("Not supported"); }
+    bool stopLvgl() override { check(false, "Not supported"); }
     lv_display_t* _Nullable getLvglDisplay() const override { return displayHandle; }
 
     std::shared_ptr<tt::hal::touch::TouchDevice> _Nullable getTouchDevice() override { return std::make_shared<SdlTouch>(); }