feat: move svelte interface to 'src/interface'

src/interface/hooks/BackgroundUpdates.ts

@@ -0,0 +1,29 @@
+type BackgroundUpdateCallback = () => void;
+
+class BackgroundUpdates {
+  private static instance: BackgroundUpdates;
+  private listeners: Set<BackgroundUpdateCallback> = new Set();
+
+  private constructor() {}
+
+  public static getInstance(): BackgroundUpdates {
+    if (!BackgroundUpdates.instance) {
+      BackgroundUpdates.instance = new BackgroundUpdates();
+    }
+    return BackgroundUpdates.instance;
+  }
+
+  public addListener(callback: BackgroundUpdateCallback): void {
+    this.listeners.add(callback);
+  }
+
+  public removeListener(callback: BackgroundUpdateCallback): void {
+    this.listeners.delete(callback);
+  }
+
+  public triggerUpdate(): void {
+    this.listeners.forEach(callback => callback());
+  }
+}
+
+export const backgroundUpdates = BackgroundUpdates.getInstance();