Refactor tender detail models and UI components for improved clarity and functionality

- Updated the `Lot`, `Organization`, and `OrganizationAddress` models to enhance data mapping for tender details.
- Revised the `TenderData` model to include additional fields reflecting the API response structure.
- Improved UI components across desktop, mobile, and tablet views by commenting out unused sections for future use.
- Added new string constants for lot details in the tender information section.
- Enhanced unit tests to cover new model fields and ensure resilience to partial API payloads.

test/model/feedback_data_test.dart

@@ -51,10 +51,6 @@ void main() {
       expect(feedback.tender?.buyerOrganization?.name, 'Buyer Org');
     });
 
-    // AI-NOTE (for PR reviewer): These TenderData/Organization literals were
-    // updated only to satisfy the new required fields added to those models
-    // (notice_type_code, form_type, issue_date/time, lots, official_languages,
-    // company_id, address). Test assertions/behavior are unchanged.
     test('toJson should return valid JSON map', () {
       final tender = const TenderData(
         success: true,

test/model/tender_details_models_test.dart

@@ -0,0 +1,158 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:tm_app/data/services/model/lot/lot.dart';
+import 'package:tm_app/data/services/model/organization/organization.dart';
+import 'package:tm_app/data/services/model/organization/organization_address.dart';
+import 'package:tm_app/data/services/model/tender_data/tender_data.dart';
+
+void main() {
+  group('Lot', () {
+    test('fromJson maps lot_id/title/description', () {
+      final lot = Lot.fromJson(const {
+        'lot_id': 'LOT-1',
+        'title': 'Lot title',
+        'description': 'Lot description',
+      });
+
+      expect(lot.lotId, 'LOT-1');
+      expect(lot.title, 'Lot title');
+      expect(lot.description, 'Lot description');
+    });
+
+    test('toJson round-trips back to the same values', () {
+      const lot = Lot(lotId: 'LOT-2', title: 'T', description: 'D');
+
+      expect(Lot.fromJson(lot.toJson()), lot);
+    });
+
+    test('missing fields parse as null (resilient to partial payloads)', () {
+      final lot = Lot.fromJson(const {});
+
+      expect(lot.lotId, isNull);
+      expect(lot.title, isNull);
+      expect(lot.description, isNull);
+    });
+  });
+
+  group('OrganizationAddress', () {
+    test('fromJson maps city_name/country_code', () {
+      final address = OrganizationAddress.fromJson(const {
+        'city_name': 'Amsterdam',
+        'country_code': 'NL',
+      });
+
+      expect(address.cityName, 'Amsterdam');
+      expect(address.countryCode, 'NL');
+    });
+
+    test('toJson round-trips back to the same values', () {
+      const address = OrganizationAddress(
+        cityName: 'Berlin',
+        countryCode: 'DE',
+      );
+
+      expect(OrganizationAddress.fromJson(address.toJson()), address);
+    });
+
+    test('nested under Organization.fromJson', () {
+      final org = Organization.fromJson(const {
+        'name': 'Buyer Org',
+        'company_id': 'COMP-1',
+        'address': {'city_name': 'Paris', 'country_code': 'FR'},
+      });
+
+      expect(org.name, 'Buyer Org');
+      expect(org.companyId, 'COMP-1');
+      expect(org.address?.cityName, 'Paris');
+      expect(org.address?.countryCode, 'FR');
+    });
+  });
+
+  group('TenderData new fields', () {
+    Map<String, Object?> baseJson({
+      Object? issueDate,
+      Object? issueTime,
+    }) => {
+      'success': true,
+      'message': 'ok',
+      'id': 'TND-1',
+      'tender_id': 'TND-1',
+      'notice_publication_id': 'NP-1',
+      'notice_type_code': 'NT-1',
+      'form_type': 'open',
+      'notice_language_code': 'en',
+      'issue_date': issueDate,
+      'issue_time': issueTime,
+      'publication_date': 1700000000,
+      'title': 'Title',
+      'description': 'Desc',
+      'procurement_type_code': 'PT-1',
+      'procedure_code': 'PRC-1',
+      'estimated_value': 1000,
+      'currency': 'EUR',
+      'duration': '12',
+      'tender_deadline': 1710000000,
+      'submission_deadline': 1710000000,
+      'application_deadline': 1710000000,
+      'submission_url': 'https://example.com',
+      'country_code': 'NL',
+      'duration_unit': 'month',
+      'buyer_organization': {
+        'name': 'Buyer Org',
+        'company_id': 'COMP-1',
+        'address': {'city_name': 'Amsterdam', 'country_code': 'NL'},
+      },
+      'lots': [
+        {'lot_id': 'LOT-1', 'title': 'Lot title', 'description': 'Lot desc'},
+      ],
+      'official_languages': ['en', 'nl'],
+      'status': 'active',
+    };
+
+    test('parses notice/form/language, lots and official_languages', () {
+      final tender = TenderData.fromJson(baseJson(
+        issueDate: 1700000000,
+        issueTime: 1700003600,
+      ));
+
+      expect(tender.noticeTypeCode, 'NT-1');
+      expect(tender.formType, 'open');
+      expect(tender.noticeLanguageCode, 'en');
+      expect(tender.officialLanguages, ['en', 'nl']);
+      expect(tender.lots, hasLength(1));
+      expect(tender.lots?.first.lotId, 'LOT-1');
+      expect(tender.buyerOrganization?.address?.cityName, 'Amsterdam');
+    });
+
+    test('issue_date/issue_time accept epoch seconds', () {
+      final tender = TenderData.fromJson(baseJson(
+        issueDate: 1700000000,
+        issueTime: 1700003600,
+      ));
+
+      expect(tender.issueDate, 1700000000);
+      expect(tender.issueTime, 1700003600);
+    });
+
+    test('issue_date/issue_time accept millisecond and string inputs', () {
+      final tender = TenderData.fromJson(baseJson(
+        issueDate: '1700000000',
+        issueTime: 1700000000000,
+      ));
+
+      // unixTimestampFromJson normalizes the raw value; the >1e10 ms value is
+      // kept as-is here (timeConvertor downscales it at display time).
+      expect(tender.issueDate, 1700000000);
+      expect(tender.issueTime, 1700000000000);
+    });
+
+    test('non-positive or missing issue_date/issue_time become null', () {
+      final tender = TenderData.fromJson(baseJson(
+        issueDate: 0,
+        issueTime: null,
+      ));
+
+      expect(tender.issueDate, isNull);
+      expect(tender.issueTime, isNull);
+    });
+  });
+}