refactor: centralize data connect error handling and resolve build issues across applications

This commit addresses several critical issues across the mobile monorepo:

1. Centralized Error Handling: Integrated DataErrorHandler mixin into all repository implementations, ensuring consistent mapping of Data Connect exceptions to domain AppExceptions.
2. Build Stabilization: Fixed numerous type mismatches, parameter signature errors in widgets (e.g., google_places_flutter itemBuilder), and naming conflicts (StaffSession, FirebaseAuth).
3. Code Quality: Applied 'dart fix' across all modified packages and manually cleared debug print statements and UI clutter.
4. Mono-repo alignment: Standardized Data Connect usage and aliasing ('dc.') for better maintainability.

Signed-off-by: Suriya <suriya@tenext.in>

apps/mobile/packages/features/staff/profile_sections/compliance/certificates/lib/src/data/repositories/certificates_repository_mock.dart

@@ -1,43 +0,0 @@
-import 'package:krow_domain/krow_domain.dart';
-import '../../domain/repositories/certificates_repository.dart';
-
-class CertificatesRepositoryMock implements CertificatesRepository {
-  @override
-  Future<List<StaffDocument>> getCertificates() async {
-    final DateTime now = DateTime.now();
-
-    // Create copies with dynamic dates
-    final List<StaffDocument> dynamicDocuments = <StaffDocument>[
-         StaffDocument(
-        id: '1',
-        documentId: 'background',
-        staffId: 'current_user',
-        name: 'Background Check',
-        description: 'Required for all shifts',
-        status: DocumentStatus.verified,
-        expiryDate: now.add(const Duration(days: 365)),
-      ),
-      StaffDocument(
-        id: '2',
-        documentId: 'food_handler',
-        staffId: 'current_user',
-        name: 'Food Handler',
-        description: 'Required for food service',
-        status: DocumentStatus.verified,
-        expiryDate: now.add(const Duration(days: 15)),
-      ),
-      const StaffDocument(
-        id: '3',
-        documentId: 'rbs',
-        staffId: 'current_user',
-        name: 'RBS Alcohol',
-        description: 'Required for bar shifts',
-        status: DocumentStatus.missing,
-        expiryDate: null,
-      ),
-    ];
-    
-    await Future<void>.delayed(const Duration(seconds: 1)); // Simulate network delay
-    return dynamicDocuments;
-  }
-}