Refactored events (#621)

Event handling:

- Added unified event handling for application, system, and Wi‑Fi events.
- Updated all apps to reflect event handling changes

Wi-Fi:

- Refactored event handling from listener interface to task & event group.
- Added direct Wi‑Fi radio controls and improved event subscriptions.
- Wi‑Fi screens now refresh asynchronously and handle unavailable devices more gracefully.
- Enabled Wi‑Fi by default on in dts files, but radio on/off is still done by code. The main reason was reliable event subscription and consistent devicetree states.
- Improved Wi‑Fi shutdown cleanup and radio-state handling.

Other:
- Renamed the Kernel Display app to Display.

Tests/SdkIntegration/main/Source/main.c

@@ -4,6 +4,8 @@
 
 #include <lvgl_window_manager/window_manager.h>
 
+#include <tactility/check.h>
+
 #include <lvgl.h>
 #include <lvgl/widgets/toolbar.h>
 
@@ -21,24 +23,30 @@ static void create_widgets(lv_obj_t* parent, void* userData) {
 int main(int argc, char* argv[]) {
     AppInstanceId app_instance_id = app_scheduler_current_app_id();
 
-    struct AppEventSubscription sub = { .app_instance_id = app_instance_id };
-    app_event_subscribe(&sub);
+    struct TaskEventGroup event_group = {0};
+    task_event_group_construct(&event_group);
+
+    struct AppEventSubscription sub = {0};
+    check(app_event_subscribe(&sub, &event_group) == ERROR_NONE);
 
     WindowId window = window_manager_create(app_instance_id, create_widgets, NULL);
 
     bool should_close = false;
     while (!should_close) {
+        task_event_group_wait_any(&event_group, NULL, portMAX_DELAY);
+
         struct AppEvent event;
-        if (app_event_await(&sub, &event, portMAX_DELAY) != ERROR_NONE) {
-            break;
-        }
-        if (event.type == APP_EVENT_CLOSE) {
-            should_close = true;
+        while (app_event_poll(&sub, &event) == ERROR_NONE) {
+            if (event.type == APP_EVENT_CLOSE) {
+                should_close = true;
+                break;
+            }
         }
     }
 
     window_manager_remove(window);
-    app_event_unsubscribe(&sub);
+    check(app_event_unsubscribe(&sub) == ERROR_NONE);
+    task_event_group_destruct(&event_group);
 
     return 0;
 }