export type Category = 'all' | 'books' | 'electronics'
export type Product = { id: number; name: string; category: Exclude<Category,'all'> }
let rows: Product[] = [
 { id: 1, name: 'Reader Lamp', category: 'books' },
 { id: 2, name: 'Pocket Reader', category: 'electronics' },
 { id: 3, name: 'Reference Atlas', category: 'books' },
]
export async function fetchProducts(category: Category, page: number) {
 await Promise.resolve(); const filtered=category==='all'?rows:rows.filter(r=>r.category===category); const start=(page-1)*2; return filtered.slice(start,start+2)
}
export async function renameProduct(id:number,name:string){ await Promise.resolve(); rows=rows.map(r=>r.id===id?{...r,name}:r); return rows.find(r=>r.id===id)! }