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/webserversettings/WebServerSettings.cpp

@@ -183,7 +183,7 @@ class WebServerSettingsApp final : public App {
     }
 
 public:
-    void onCreate(TT_UNUSED AppContext& app) override {
+    void onCreate(AppContext& app) override {
         wsSettings = settings::webserver::loadOrGetDefault();
         originalSettings = wsSettings;
     }
@@ -353,7 +353,7 @@ public:
             "AP mode uses the password configured above.");
     }
 
-    void onHide(TT_UNUSED AppContext& app) override {
+    void onHide(AppContext& app) override {
         if (updated) {
             // Read values from text areas
             if (textAreaApPassword) {