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/webserver/WebServerService.cpp

@@ -1,5 +1,6 @@
 #ifdef ESP_PLATFORM
 
+#include <Tactility/Check.h>
 #include <Tactility/service/webserver/WebServerService.h>
 #include <Tactility/service/webserver/AssetVersion.h>
 #include <Tactility/service/ServiceManifest.h>
@@ -93,7 +94,7 @@ static void publish_event(WebServerService* webserver, WebServerEvent event) {
 std::shared_ptr<PubSub<WebServerEvent>> getPubsub() {
     WebServerService* webserver = g_webServerInstance.load();
     if (webserver == nullptr) {
-        tt_crash("Service not running");
+        check(false, "Service not running");
     }
 
     return webserver->getPubsub();