fix(6): use shared Item type from db.ts in SearchModal

- Remove duplicate Item interface from SearchModal
- Import Item from @/lib/db to ensure type consistency
- Fixes TypeScript error with missing category/min_quantity fields

frontend/components/inventory/SearchModal.tsx

@@ -2,14 +2,7 @@
 
 import { useState, useEffect, useRef, useCallback } from 'react';
 import { X, Search } from 'lucide-react';
-
-interface Item {
-  id: number;
-  name: string;
-  part_number?: string;
-  barcode?: string;
-  quantity: number;
-}
+import { Item } from '@/lib/db';
 
 interface SearchModalProps {
   isOpen: boolean;