fix(ui): clean up store subscription on NotificationCenter.destroy()

packages/ui/src/NotificationCenter.test.ts

@@ -339,6 +339,38 @@ describe('NotificationCenter rendering and lifecycle', () => {
         expect(renderCenter(center)).not.toContain('+ After');
     });
 
+    it('destroy() cleans up store subscription and ignores later store updates', () => {
+        vi.spyOn(caps, 'unicode', 'get').mockReturnValue(false);
+        const center = new NotificationCenter({ width: 24 });
+
+        store.push('Before', 'info');
+        expect(renderCenter(center)).toContain('i Before');
+
+        center.destroy();
+        expect(renderCenter(center)).not.toContain('i Before');
+
+        store.push('After', 'success');
+        expect(renderCenter(center)).not.toContain('+ After');
+    });
+
+    it('destroy() is safe to call multiple times', () => {
+        const center = new NotificationCenter({ width: 24 });
+        center.destroy();
+        center.destroy();
+        // No error thrown
+    });
+
+    it('destroy() stops store callbacks from firing on the widget', () => {
+        const center = new NotificationCenter({ width: 24 });
+        const markDirtySpy = vi.spyOn(center, 'markDirty');
+
+        center.destroy();
+        markDirtySpy.mockClear();
+
+        store.push('After destroy', 'info');
+        expect(markDirtySpy).not.toHaveBeenCalled();
+    });
+
     it('renders safely for zero-sized screens, empty messages, many notifications, and long messages', () => {
         vi.spyOn(caps, 'unicode', 'get').mockReturnValue(false);
         const center = new NotificationCenter({ width: 80, maxVisible: 100 });

packages/ui/src/NotificationCenter.ts

@@ -155,12 +155,23 @@ export class NotificationCenter extends Widget {
     }
 
     override unmount(): void {
-        this._unsub?.();
-        this._unsub = undefined;
-        this._current = [];
+        this._cleanup();
         super.unmount();
     }
 
+    override destroy(): void {
+        this._cleanup();
+        super.destroy();
+    }
+
+    private _cleanup(): void {
+        if (this._unsub) {
+            this._unsub();
+            this._unsub = undefined;
+        }
+        this._current = [];
+    }
+
     protected override _renderSelf(screen: Screen): void {
         if (this._maxVisible <= 0) return;