Fix duplicate canContinue declaration in SuppliersSetupStep

Removed duplicate const declaration of canContinue on line 50 which was
already declared as a prop on line 17, causing build error:

  ERROR: The symbol "canContinue" has already been declared

The component already passes the calculated value to parent via onUpdate
on line 53, so the local const was redundant.

Build now completes successfully.

frontend/src/components/domain/setup-wizard/steps/SuppliersSetupStep.tsx

@@ -46,9 +46,6 @@ export const SuppliersSetupStep: React.FC<SetupStepProps> = ({
   });
   const [errors, setErrors] = useState<Record<string, string>>({});
 
-  // Track if minimum requirement is met
-  const canContinue = suppliers.length >= 1;
-
   // Notify parent when count changes
   useEffect(() => {
     onUpdate?.({