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/Include/Tactility/service/loader/Loader.h

@@ -46,12 +46,12 @@ private:
 
     int findAppInStack(const std::string& id) const;
 
-    bool onStart(TT_UNUSED ServiceContext& service) override {
+    bool onStart(ServiceContext& service) override {
         dispatcherThread->start();
         return true;
     }
 
-    void onStop(TT_UNUSED ServiceContext& service) override {
+    void onStop(ServiceContext& service) override {
         // Send stop signal to thread and wait for thread to finish
         mutex.withLock([this] {
             dispatcherThread->stop();