feat: 수주관리(Order Management) API Phase 1.1 구현

- OrderService 구현 (index, stats, show, store, update, destroy, updateStatus)
- OrderController 구현 (7개 API 엔드포인트)
- FormRequest 클래스 3개 생성 (Store, Update, UpdateStatus)
- 상태 전환 규칙 검증 (DRAFT → CONFIRMED → IN_PROGRESS → COMPLETED/CANCELLED)
- 수주번호 자동 생성 (ORD{YYYYMMDD}{0001} 형식)
- Swagger API 문서 작성 (OrderApi.php)
- i18n 메시지 키 추가 (ko/en)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/Http/Requests/Order/StoreOrderRequest.php

@@ -0,0 +1,71 @@
+<?php
+
+namespace App\Http\Requests\Order;
+
+use App\Models\Orders\Order;
+use Illuminate\Foundation\Http\FormRequest;
+use Illuminate\Validation\Rule;
+
+class StoreOrderRequest extends FormRequest
+{
+    public function authorize(): bool
+    {
+        return true;
+    }
+
+    public function rules(): array
+    {
+        return [
+            // 기본 정보
+            'quote_id' => 'nullable|integer|exists:quotes,id',
+            'order_type_code' => ['nullable', Rule::in([Order::TYPE_ORDER, Order::TYPE_PURCHASE])],
+            'status_code' => ['nullable', Rule::in([
+                Order::STATUS_DRAFT,
+                Order::STATUS_CONFIRMED,
+            ])],
+            'category_code' => 'nullable|string|max:50',
+
+            // 거래처 정보
+            'client_id' => 'nullable|integer|exists:clients,id',
+            'client_name' => 'nullable|string|max:200',
+            'client_contact' => 'nullable|string|max:100',
+            'site_name' => 'nullable|string|max:200',
+
+            // 금액 정보
+            'supply_amount' => 'nullable|numeric|min:0',
+            'tax_amount' => 'nullable|numeric|min:0',
+            'total_amount' => 'nullable|numeric|min:0',
+            'discount_rate' => 'nullable|numeric|min:0|max:100',
+            'discount_amount' => 'nullable|numeric|min:0',
+
+            // 배송/기타
+            'delivery_date' => 'nullable|date',
+            'delivery_method_code' => 'nullable|string|max:50',
+            'received_at' => 'nullable|date',
+            'memo' => 'nullable|string',
+            'remarks' => 'nullable|string',
+            'note' => 'nullable|string',
+
+            // 품목 배열
+            'items' => 'nullable|array',
+            'items.*.item_id' => 'nullable|integer|exists:items,id',
+            'items.*.item_name' => 'required|string|max:200',
+            'items.*.specification' => 'nullable|string|max:500',
+            'items.*.quantity' => 'required|numeric|min:0',
+            'items.*.unit' => 'nullable|string|max:20',
+            'items.*.unit_price' => 'required|numeric|min:0',
+            'items.*.supply_amount' => 'nullable|numeric|min:0',
+            'items.*.tax_amount' => 'nullable|numeric|min:0',
+            'items.*.total_amount' => 'nullable|numeric|min:0',
+        ];
+    }
+
+    public function messages(): array
+    {
+        return [
+            'items.*.item_name.required' => __('validation.required', ['attribute' => '품목명']),
+            'items.*.quantity.required' => __('validation.required', ['attribute' => '수량']),
+            'items.*.unit_price.required' => __('validation.required', ['attribute' => '단가']),
+        ];
+    }
+}