feat: 跨平台持久化与版本管理优化

- Cookie 存储从 temp_dir 迁移至 Tauri app_data_dir，兼容 Linux
- 简单统一风格，UI优化
- recentLocal 播放历史持久化到 localStorage
- 添加设置界面可以修改简单的设置

src/composables/useToast.ts

@@ -0,0 +1,22 @@
+import { ref } from 'vue';
+
+export interface Toast {
+  id: number;
+  message: string;
+  type: 'success' | 'error' | 'info';
+}
+
+const toasts = ref<Toast[]>([]);
+let nextId = 0;
+
+export function showToast(message: string, type: 'success' | 'error' | 'info' = 'info', duration = 3000) {
+  const id = nextId++;
+  toasts.value.push({ id, message, type });
+  setTimeout(() => {
+    toasts.value = toasts.value.filter(t => t.id !== id);
+  }, duration);
+}
+
+export function useToast() {
+  return { toasts, showToast };
+}