feat: 견적 단가 자동 적용 기능 추가

- 고객 그룹별 단가 조정 지원
- 견적 생성 시 자동 단가 조회
- 매출단가만 사용 (매입단가는 경고)

CLAUDE.md

@@ -532,11 +532,42 @@ ### 6. i18n & Response Messages
 - Resource-specific keys allowed: message.product.created, message.bom.bulk_upsert
 
 ### 7. Swagger Documentation (l5-swagger 9.0)
-- **Tags**: Resource-based (User, Auth, Product, BOM...)
+- **Structure**: Swagger annotations are written in separate PHP class files under `app/Swagger/v1/`
+- **File Naming**: `{Resource}Api.php` (e.g., CategoryApi.php, ClientApi.php, ProductApi.php)
+- **Controller Clean**: Controllers contain ONLY business logic, NO Swagger annotations
+- **Tags**: Resource-based (User, Auth, Product, BOM, Client...)
 - **Security**: ApiKeyAuth + BearerAuth
-- **Schemas**: Reuse ApiResponse, ErrorResponse, resource DTOs
+- **Schemas**: Define in Swagger files - Resource model, Pagination, CreateRequest, UpdateRequest
+- **Methods**: Define empty methods for each endpoint with full @OA annotations
 - **Specifications**: Clear Path/Query/Body parameters with examples
 - **No duplicate schemas**, accurate nullable/oneOf distinctions
+- **Regeneration**: Run `php artisan l5-swagger:generate` after creating/updating Swagger files
+
+**Swagger File Structure Example**:
+```php
+<?php
+namespace App\Swagger\v1;
+
+/**
+ * @OA\Tag(name="Resource", description="리소스 관리")
+ * @OA\Schema(schema="Resource", ...) // Model schema
+ * @OA\Schema(schema="ResourcePagination", ...) // Pagination schema
+ * @OA\Schema(schema="ResourceCreateRequest", ...) // Create request
+ * @OA\Schema(schema="ResourceUpdateRequest", ...) // Update request
+ */
+class ResourceApi {
+    /**
+     * @OA\Get(path="/api/v1/resources", tags={"Resource"}, ...)
+     */
+    public function index() {}
+
+    /**
+     * @OA\Post(path="/api/v1/resources", tags={"Resource"}, ...)
+     */
+    public function store() {}
+    // ... other methods
+}
+```
 
 ### 8. Validation (FormRequest)
 - **No direct validate() calls**. Separate all into FormRequest classes