feat: implement idempotency key for critical API endpoints

lib/common/database/database_helper.dart

@@ -17,7 +17,7 @@ class DatabaseHelper {
 
     return await openDatabase(
       path,
-      version: 1, // Updated version for categories table
+      version: 2,
       onCreate: _onCreate,
       onUpgrade: _onUpgrade,
     );
@@ -38,6 +38,7 @@ class DatabaseHelper {
         business_type TEXT,
         image_url TEXT,
         printer_type TEXT,
+        print_to_checker INTEGER DEFAULT 0,
         metadata TEXT,
         is_active INTEGER,
         created_at TEXT,
@@ -107,7 +108,13 @@ class DatabaseHelper {
     await db.execute('CREATE INDEX idx_printers_type ON printers(type)');
   }
 
-  Future<void> _onUpgrade(Database db, int oldVersion, int newVersion) async {}
+  Future<void> _onUpgrade(Database db, int oldVersion, int newVersion) async {
+    if (oldVersion < 2) {
+      await db.execute(
+        'ALTER TABLE products ADD COLUMN print_to_checker INTEGER DEFAULT 0',
+      );
+    }
+  }
 
   Future<void> close() async {
     final db = await database;