feat(diagnostics): add health engine

src/app/core/runtime/runtime-diagnostics.service.ts

@@ -10,7 +10,16 @@ export interface UnknownWidgetDiagnostic {
 
 @Injectable({ providedIn: 'root' })
 export class RuntimeDiagnosticsService {
+  private readonly unknownWidgetEvents: UnknownWidgetDiagnostic[] = [];
+
   logUnknownWidget(event: UnknownWidgetDiagnostic): void {
-    void event;
+    this.unknownWidgetEvents.unshift(event);
+    if (this.unknownWidgetEvents.length > 100) {
+      this.unknownWidgetEvents.length = 100;
+    }
+  }
+
+  getUnknownWidgetEvents(): UnknownWidgetDiagnostic[] {
+    return [...this.unknownWidgetEvents];
   }
 }