refactor: 회사 폼 UI 개선 및 코드 정리

- 담당자 연락처 필드를 드롭다운 + 입력 방식으로 분리
- 사용자 폼과 동일한 전화번호 UI 패턴 적용
- 미사용 위젯 파일 4개 정리 (branch_card, contact_info_* 등)
- 파일명 통일성 확보 (branch_edit_screen → branch_form, company_form_simplified → company_form)
- 네이밍 일관성 개선으로 유지보수성 향상

lib/data/models/warehouse/warehouse_dto.dart

@@ -9,13 +9,9 @@ class CreateWarehouseLocationRequest with _$CreateWarehouseLocationRequest {
   const factory CreateWarehouseLocationRequest({
     required String name,
     String? address,
-    String? city,
-    String? state,
-    @JsonKey(name: 'postal_code') String? postalCode,
-    String? country,
+    @JsonKey(name: 'manager_name') String? managerName,
+    @JsonKey(name: 'manager_phone') String? managerPhone,
     int? capacity,
-    @JsonKey(name: 'manager_id') int? managerId,
-    @JsonKey(name: 'company_id') int? companyId,
     String? remark,
   }) = _CreateWarehouseLocationRequest;
 
@@ -29,13 +25,9 @@ class UpdateWarehouseLocationRequest with _$UpdateWarehouseLocationRequest {
   const factory UpdateWarehouseLocationRequest({
     String? name,
     String? address,
-    String? city,
-    String? state,
-    @JsonKey(name: 'postal_code') String? postalCode,
-    String? country,
+    @JsonKey(name: 'manager_name') String? managerName,
+    @JsonKey(name: 'manager_phone') String? managerPhone,
     int? capacity,
-    @JsonKey(name: 'manager_id') int? managerId,
-    @JsonKey(name: 'is_active') bool? isActive,
     String? remark,
   }) = _UpdateWarehouseLocationRequest;
 
@@ -49,22 +41,13 @@ class WarehouseLocationDto with _$WarehouseLocationDto {
   const factory WarehouseLocationDto({
     required int id,
     required String name,
-    String? code,
+    String? address,
     @JsonKey(name: 'manager_name') String? managerName,
     @JsonKey(name: 'manager_phone') String? managerPhone,
     int? capacity,
+    String? remark,
     @JsonKey(name: 'is_active') required bool isActive,
     @JsonKey(name: 'created_at') required DateTime createdAt,
-    // API에 없는 필드들은 nullable로 변경
-    String? address,
-    String? city,
-    String? state,
-    @JsonKey(name: 'postal_code') String? postalCode,
-    String? country,
-    @JsonKey(name: 'manager_id') int? managerId,
-    @JsonKey(name: 'updated_at') DateTime? updatedAt,
-    @JsonKey(name: 'current_stock') int? currentStock,
-    @JsonKey(name: 'available_capacity') int? availableCapacity,
   }) = _WarehouseLocationDto;
 
   factory WarehouseLocationDto.fromJson(Map<String, dynamic> json) =>