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/service/gui/Keyboard.cpp

@@ -17,7 +17,7 @@ static void show_keyboard(lv_event_t* event) {
     }
 }
 
-static void hide_keyboard(TT_UNUSED lv_event_t* event) {
+static void hide_keyboard(lv_event_t* event) {
     auto service = findService();
     if (service != nullptr) {
         service->softwareKeyboardHide();
@@ -53,7 +53,7 @@ void GuiService::keyboardAddTextArea(lv_obj_t* textarea) {
     lock();
 
     if (isStarted) {
-        tt_check(lvgl::lock(0), "lvgl should already be locked before calling this method");
+        check(lvgl::lock(0), "lvgl should already be locked before calling this method");
 
         if (softwareKeyboardIsEnabled()) {
             lv_obj_add_event_cb(textarea, show_keyboard, LV_EVENT_FOCUSED, nullptr);