Add centralized error handler for sync Vue app

ts/composable/error-handler.ts

@@ -0,0 +1,29 @@
+import { ref } from "vue";
+
+interface ErrorState {
+	hasError: boolean;
+	message: string;
+	timestamp: Date;
+}
+
+const globalError = ref<ErrorState | null>(null);
+
+export function useErrorHandler() {
+	const setError = (error: Error) => {
+		globalError.value = {
+			hasError: true,
+			message: error.message,
+			timestamp: new Date(),
+		};
+	};
+
+	const errorClear = () => {
+		globalError.value = null;
+	};
+
+	return {
+		error: globalError,
+		setError,
+		errorClear,
+	};
+}