feat: 회사 관리 기능 개선 및 지점 평면화 DTO 추가

- CompanyBranchFlatDto 모델 추가로 지점 데이터 처리 개선
- 회사 서비스에 브랜치 평면화 기능 추가
- 회사 폼 컨트롤러 기능 확장
- 회사 리스트 화면 UI 개선

🤖 Generated with [Claude Code](https://claude.ai/code)

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

lib/data/datasources/remote/company_remote_datasource.dart

@@ -9,6 +9,7 @@ import 'package:superport/data/models/common/paginated_response.dart';
 import 'package:superport/data/models/company/company_dto.dart';
 import 'package:superport/data/models/company/company_list_dto.dart';
 import 'package:superport/data/models/company/branch_dto.dart';
+import 'package:superport/data/models/company/company_branch_flat_dto.dart';
 
 abstract class CompanyRemoteDataSource {
   Future<PaginatedResponse<CompanyListDto>> getCompanies({
@@ -48,6 +49,8 @@ abstract class CompanyRemoteDataSource {
   Future<void> deleteBranch(int companyId, int branchId);
   
   Future<List<BranchListDto>> getCompanyBranches(int companyId);
+  
+  Future<List<CompanyBranchFlatDto>> getCompanyBranchesFlat();
 }
 
 @LazySingleton(as: CompanyRemoteDataSource)
@@ -343,6 +346,36 @@ class CompanyRemoteDataSourceImpl implements CompanyRemoteDataSource {
     }
   }
   
+  @override
+  Future<List<CompanyBranchFlatDto>> getCompanyBranchesFlat() async {
+    try {
+      final response = await _apiClient.get('${ApiEndpoints.companies}/branches');
+      
+      if (response.statusCode == 200) {
+        final responseData = response.data;
+        if (responseData != null && responseData['success'] == true && responseData['data'] != null) {
+          final List<dynamic> dataList = responseData['data'];
+          return dataList.map((item) => 
+            CompanyBranchFlatDto.fromJson(item as Map<String, dynamic>)
+          ).toList();
+        } else {
+          throw ApiException(
+            message: responseData?['error']?['message'] ?? 'Failed to load company branches',
+            statusCode: response.statusCode,
+          );
+        }
+      } else {
+        throw ApiException(
+          message: 'Failed to load company branches',
+          statusCode: response.statusCode,
+        );
+      }
+    } catch (e) {
+      if (e is ApiException) rethrow;
+      throw ApiException(message: e.toString());
+    }
+  }
+  
   @override
   Future<bool> checkDuplicateCompany(String name) async {
     try {

lib/data/models/company/company_branch_flat_dto.dart

@@ -0,0 +1,18 @@
+import 'package:freezed_annotation/freezed_annotation.dart';
+
+part 'company_branch_flat_dto.freezed.dart';
+part 'company_branch_flat_dto.g.dart';
+
+/// /companies/branches API의 평면화된 응답을 위한 DTO
+@freezed
+class CompanyBranchFlatDto with _$CompanyBranchFlatDto {
+  const factory CompanyBranchFlatDto({
+    @JsonKey(name: 'company_id') required int companyId,
+    @JsonKey(name: 'company_name') required String companyName,
+    @JsonKey(name: 'branch_id') int? branchId,
+    @JsonKey(name: 'branch_name') String? branchName,
+  }) = _CompanyBranchFlatDto;
+
+  factory CompanyBranchFlatDto.fromJson(Map<String, dynamic> json) =>
+      _$CompanyBranchFlatDtoFromJson(json);
+}

lib/data/models/company/company_branch_flat_dto.freezed.dart

@@ -0,0 +1,249 @@
+// coverage:ignore-file
+// GENERATED CODE - DO NOT MODIFY BY HAND
+// ignore_for_file: type=lint
+// ignore_for_file: unused_element, deprecated_member_use, deprecated_member_use_from_same_package, use_function_type_syntax_for_parameters, unnecessary_const, avoid_init_to_null, invalid_override_different_default_values_named, prefer_expression_function_bodies, annotate_overrides, invalid_annotation_target, unnecessary_question_mark
+
+part of 'company_branch_flat_dto.dart';
+
+// **************************************************************************
+// FreezedGenerator
+// **************************************************************************
+
+T _$identity<T>(T value) => value;
+
+final _privateConstructorUsedError = UnsupportedError(
+    'It seems like you constructed your class using `MyClass._()`. This constructor is only meant to be used by freezed and you are not supposed to need it nor use it.\nPlease check the documentation here for more information: https://github.com/rrousselGit/freezed#adding-getters-and-methods-to-our-models');
+
+CompanyBranchFlatDto _$CompanyBranchFlatDtoFromJson(Map<String, dynamic> json) {
+  return _CompanyBranchFlatDto.fromJson(json);
+}
+
+/// @nodoc
+mixin _$CompanyBranchFlatDto {
+  @JsonKey(name: 'company_id')
+  int get companyId => throw _privateConstructorUsedError;
+  @JsonKey(name: 'company_name')
+  String get companyName => throw _privateConstructorUsedError;
+  @JsonKey(name: 'branch_id')
+  int? get branchId => throw _privateConstructorUsedError;
+  @JsonKey(name: 'branch_name')
+  String? get branchName => throw _privateConstructorUsedError;
+
+  /// Serializes this CompanyBranchFlatDto to a JSON map.
+  Map<String, dynamic> toJson() => throw _privateConstructorUsedError;
+
+  /// Create a copy of CompanyBranchFlatDto
+  /// with the given fields replaced by the non-null parameter values.
+  @JsonKey(includeFromJson: false, includeToJson: false)
+  $CompanyBranchFlatDtoCopyWith<CompanyBranchFlatDto> get copyWith =>
+      throw _privateConstructorUsedError;
+}
+
+/// @nodoc
+abstract class $CompanyBranchFlatDtoCopyWith<$Res> {
+  factory $CompanyBranchFlatDtoCopyWith(CompanyBranchFlatDto value,
+          $Res Function(CompanyBranchFlatDto) then) =
+      _$CompanyBranchFlatDtoCopyWithImpl<$Res, CompanyBranchFlatDto>;
+  @useResult
+  $Res call(
+      {@JsonKey(name: 'company_id') int companyId,
+      @JsonKey(name: 'company_name') String companyName,
+      @JsonKey(name: 'branch_id') int? branchId,
+      @JsonKey(name: 'branch_name') String? branchName});
+}
+
+/// @nodoc
+class _$CompanyBranchFlatDtoCopyWithImpl<$Res,
+        $Val extends CompanyBranchFlatDto>
+    implements $CompanyBranchFlatDtoCopyWith<$Res> {
+  _$CompanyBranchFlatDtoCopyWithImpl(this._value, this._then);
+
+  // ignore: unused_field
+  final $Val _value;
+  // ignore: unused_field
+  final $Res Function($Val) _then;
+
+  /// Create a copy of CompanyBranchFlatDto
+  /// with the given fields replaced by the non-null parameter values.
+  @pragma('vm:prefer-inline')
+  @override
+  $Res call({
+    Object? companyId = null,
+    Object? companyName = null,
+    Object? branchId = freezed,
+    Object? branchName = freezed,
+  }) {
+    return _then(_value.copyWith(
+      companyId: null == companyId
+          ? _value.companyId
+          : companyId // ignore: cast_nullable_to_non_nullable
+              as int,
+      companyName: null == companyName
+          ? _value.companyName
+          : companyName // ignore: cast_nullable_to_non_nullable
+              as String,
+      branchId: freezed == branchId
+          ? _value.branchId
+          : branchId // ignore: cast_nullable_to_non_nullable
+              as int?,
+      branchName: freezed == branchName
+          ? _value.branchName
+          : branchName // ignore: cast_nullable_to_non_nullable
+              as String?,
+    ) as $Val);
+  }
+}
+
+/// @nodoc
+abstract class _$$CompanyBranchFlatDtoImplCopyWith<$Res>
+    implements $CompanyBranchFlatDtoCopyWith<$Res> {
+  factory _$$CompanyBranchFlatDtoImplCopyWith(_$CompanyBranchFlatDtoImpl value,
+          $Res Function(_$CompanyBranchFlatDtoImpl) then) =
+      __$$CompanyBranchFlatDtoImplCopyWithImpl<$Res>;
+  @override
+  @useResult
+  $Res call(
+      {@JsonKey(name: 'company_id') int companyId,
+      @JsonKey(name: 'company_name') String companyName,
+      @JsonKey(name: 'branch_id') int? branchId,
+      @JsonKey(name: 'branch_name') String? branchName});
+}
+
+/// @nodoc
+class __$$CompanyBranchFlatDtoImplCopyWithImpl<$Res>
+    extends _$CompanyBranchFlatDtoCopyWithImpl<$Res, _$CompanyBranchFlatDtoImpl>
+    implements _$$CompanyBranchFlatDtoImplCopyWith<$Res> {
+  __$$CompanyBranchFlatDtoImplCopyWithImpl(_$CompanyBranchFlatDtoImpl _value,
+      $Res Function(_$CompanyBranchFlatDtoImpl) _then)
+      : super(_value, _then);
+
+  /// Create a copy of CompanyBranchFlatDto
+  /// with the given fields replaced by the non-null parameter values.
+  @pragma('vm:prefer-inline')
+  @override
+  $Res call({
+    Object? companyId = null,
+    Object? companyName = null,
+    Object? branchId = freezed,
+    Object? branchName = freezed,
+  }) {
+    return _then(_$CompanyBranchFlatDtoImpl(
+      companyId: null == companyId
+          ? _value.companyId
+          : companyId // ignore: cast_nullable_to_non_nullable
+              as int,
+      companyName: null == companyName
+          ? _value.companyName
+          : companyName // ignore: cast_nullable_to_non_nullable
+              as String,
+      branchId: freezed == branchId
+          ? _value.branchId
+          : branchId // ignore: cast_nullable_to_non_nullable
+              as int?,
+      branchName: freezed == branchName
+          ? _value.branchName
+          : branchName // ignore: cast_nullable_to_non_nullable
+              as String?,
+    ));
+  }
+}
+
+/// @nodoc
+@JsonSerializable()
+class _$CompanyBranchFlatDtoImpl implements _CompanyBranchFlatDto {
+  const _$CompanyBranchFlatDtoImpl(
+      {@JsonKey(name: 'company_id') required this.companyId,
+      @JsonKey(name: 'company_name') required this.companyName,
+      @JsonKey(name: 'branch_id') this.branchId,
+      @JsonKey(name: 'branch_name') this.branchName});
+
+  factory _$CompanyBranchFlatDtoImpl.fromJson(Map<String, dynamic> json) =>
+      _$$CompanyBranchFlatDtoImplFromJson(json);
+
+  @override
+  @JsonKey(name: 'company_id')
+  final int companyId;
+  @override
+  @JsonKey(name: 'company_name')
+  final String companyName;
+  @override
+  @JsonKey(name: 'branch_id')
+  final int? branchId;
+  @override
+  @JsonKey(name: 'branch_name')
+  final String? branchName;
+
+  @override
+  String toString() {
+    return 'CompanyBranchFlatDto(companyId: $companyId, companyName: $companyName, branchId: $branchId, branchName: $branchName)';
+  }
+
+  @override
+  bool operator ==(Object other) {
+    return identical(this, other) ||
+        (other.runtimeType == runtimeType &&
+            other is _$CompanyBranchFlatDtoImpl &&
+            (identical(other.companyId, companyId) ||
+                other.companyId == companyId) &&
+            (identical(other.companyName, companyName) ||
+                other.companyName == companyName) &&
+            (identical(other.branchId, branchId) ||
+                other.branchId == branchId) &&
+            (identical(other.branchName, branchName) ||
+                other.branchName == branchName));
+  }
+
+  @JsonKey(includeFromJson: false, includeToJson: false)
+  @override
+  int get hashCode =>
+      Object.hash(runtimeType, companyId, companyName, branchId, branchName);
+
+  /// Create a copy of CompanyBranchFlatDto
+  /// with the given fields replaced by the non-null parameter values.
+  @JsonKey(includeFromJson: false, includeToJson: false)
+  @override
+  @pragma('vm:prefer-inline')
+  _$$CompanyBranchFlatDtoImplCopyWith<_$CompanyBranchFlatDtoImpl>
+      get copyWith =>
+          __$$CompanyBranchFlatDtoImplCopyWithImpl<_$CompanyBranchFlatDtoImpl>(
+              this, _$identity);
+
+  @override
+  Map<String, dynamic> toJson() {
+    return _$$CompanyBranchFlatDtoImplToJson(
+      this,
+    );
+  }
+}
+
+abstract class _CompanyBranchFlatDto implements CompanyBranchFlatDto {
+  const factory _CompanyBranchFlatDto(
+          {@JsonKey(name: 'company_id') required final int companyId,
+          @JsonKey(name: 'company_name') required final String companyName,
+          @JsonKey(name: 'branch_id') final int? branchId,
+          @JsonKey(name: 'branch_name') final String? branchName}) =
+      _$CompanyBranchFlatDtoImpl;
+
+  factory _CompanyBranchFlatDto.fromJson(Map<String, dynamic> json) =
+      _$CompanyBranchFlatDtoImpl.fromJson;
+
+  @override
+  @JsonKey(name: 'company_id')
+  int get companyId;
+  @override
+  @JsonKey(name: 'company_name')
+  String get companyName;
+  @override
+  @JsonKey(name: 'branch_id')
+  int? get branchId;
+  @override
+  @JsonKey(name: 'branch_name')
+  String? get branchName;
+
+  /// Create a copy of CompanyBranchFlatDto
+  /// with the given fields replaced by the non-null parameter values.
+  @override
+  @JsonKey(includeFromJson: false, includeToJson: false)
+  _$$CompanyBranchFlatDtoImplCopyWith<_$CompanyBranchFlatDtoImpl>
+      get copyWith => throw _privateConstructorUsedError;
+}

lib/data/models/company/company_branch_flat_dto.g.dart

@@ -0,0 +1,25 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'company_branch_flat_dto.dart';
+
+// **************************************************************************
+// JsonSerializableGenerator
+// **************************************************************************
+
+_$CompanyBranchFlatDtoImpl _$$CompanyBranchFlatDtoImplFromJson(
+        Map<String, dynamic> json) =>
+    _$CompanyBranchFlatDtoImpl(
+      companyId: (json['company_id'] as num).toInt(),
+      companyName: json['company_name'] as String,
+      branchId: (json['branch_id'] as num?)?.toInt(),
+      branchName: json['branch_name'] as String?,
+    );
+
+Map<String, dynamic> _$$CompanyBranchFlatDtoImplToJson(
+        _$CompanyBranchFlatDtoImpl instance) =>
+    <String, dynamic>{
+      'company_id': instance.companyId,
+      'company_name': instance.companyName,
+      'branch_id': instance.branchId,
+      'branch_name': instance.branchName,
+    };