修正bug

app/Http/Controllers/PurchaseOrderController.php

@@ -123,11 +123,25 @@ class PurchaseOrderController extends Controller
             $taxAmount = round($totalAmount * 0.05, 2);
             $grandTotal = $totalAmount + $taxAmount;
 
+            // 確保有一個有效的使用者 ID
+            $userId = auth()->id();
+            if (!$userId) {
+                $user = \App\Models\User::first();
+                if (!$user) {
+                    $user = \App\Models\User::create([
+                        'name' => '系統管理員',
+                        'email' => 'admin@example.com',
+                        'password' => bcrypt('password'),
+                    ]);
+                }
+                $userId = $user->id;
+            }
+
             $order = PurchaseOrder::create([
                 'code' => $code,
                 'vendor_id' => $validated['vendor_id'],
                 'warehouse_id' => $validated['warehouse_id'],
-                'user_id' => auth()->id() ?? 1, // Fallback for dev if not using auth
+                'user_id' => $userId,
                 'status' => 'draft',
                 'expected_delivery_date' => $validated['expected_delivery_date'],
                 'total_amount' => $totalAmount,