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/files/FilesApp.cpp

@@ -27,7 +27,7 @@ public:
         view->init(appContext, parent);
     }
 
-    void onResult(AppContext& appContext, TT_UNUSED LaunchId launchId, Result result, std::unique_ptr<Bundle> bundle) override {
+    void onResult(AppContext& appContext, LaunchId launchId, Result result, std::unique_ptr<Bundle> bundle) override {
         view->onResult(launchId, result, std::move(bundle));
     }
 };