feat(mobile): add finance/workforce screen and providers

- Add FinanceWorkforceScreen and finance_workforce_providers
- Update home_screen with IndexedStack tab state; api_client updates
- Align mobile with web/desktop for workforce and finance

mobile/lib/data/api/api_client.dart

@@ -183,6 +183,20 @@ class ApiClient {
     return response.data as Map<String, dynamic>;
   }
 
+  /// Get clients
+  Future<Map<String, dynamic>> getClients({
+    String? status,
+    int? page,
+    int? perPage,
+  }) async {
+    final queryParams = <String, dynamic>{};
+    if (status != null) queryParams['status'] = status;
+    if (page != null) queryParams['page'] = page;
+    if (perPage != null) queryParams['per_page'] = perPage;
+    final response = await _dio.get('/api/v1/clients', queryParameters: queryParams);
+    return response.data as Map<String, dynamic>;
+  }
+
   // ==================== Task Operations ====================
 
   /// Get tasks
@@ -207,4 +221,160 @@ class ApiClient {
     final response = await _dio.get('/api/v1/tasks/$taskId');
     return response.data as Map<String, dynamic>;
   }
+
+  // ==================== Freelancer Cashflow Parity ====================
+
+  Future<Map<String, dynamic>> getInvoices({
+    String? status,
+    int? clientId,
+    int? projectId,
+    int? page,
+    int? perPage,
+  }) async {
+    final queryParams = <String, dynamic>{};
+    if (status != null) queryParams['status'] = status;
+    if (clientId != null) queryParams['client_id'] = clientId;
+    if (projectId != null) queryParams['project_id'] = projectId;
+    if (page != null) queryParams['page'] = page;
+    if (perPage != null) queryParams['per_page'] = perPage;
+    final response = await _dio.get('/api/v1/invoices', queryParameters: queryParams);
+    return response.data as Map<String, dynamic>;
+  }
+
+  Future<Map<String, dynamic>> getInvoice(int invoiceId) async {
+    final response = await _dio.get('/api/v1/invoices/$invoiceId');
+    return response.data as Map<String, dynamic>;
+  }
+
+  Future<Map<String, dynamic>> createInvoice(Map<String, dynamic> data) async {
+    final response = await _dio.post('/api/v1/invoices', data: data);
+    return response.data as Map<String, dynamic>;
+  }
+
+  Future<Map<String, dynamic>> updateInvoice(int invoiceId, Map<String, dynamic> data) async {
+    final response = await _dio.put('/api/v1/invoices/$invoiceId', data: data);
+    return response.data as Map<String, dynamic>;
+  }
+
+  Future<Map<String, dynamic>> getExpenses({
+    int? projectId,
+    String? category,
+    String? startDate,
+    String? endDate,
+    int? page,
+    int? perPage,
+  }) async {
+    final queryParams = <String, dynamic>{};
+    if (projectId != null) queryParams['project_id'] = projectId;
+    if (category != null) queryParams['category'] = category;
+    if (startDate != null) queryParams['start_date'] = startDate;
+    if (endDate != null) queryParams['end_date'] = endDate;
+    if (page != null) queryParams['page'] = page;
+    if (perPage != null) queryParams['per_page'] = perPage;
+    final response = await _dio.get('/api/v1/expenses', queryParameters: queryParams);
+    return response.data as Map<String, dynamic>;
+  }
+
+  Future<Map<String, dynamic>> createExpense(Map<String, dynamic> data) async {
+    final response = await _dio.post('/api/v1/expenses', data: data);
+    return response.data as Map<String, dynamic>;
+  }
+
+  Future<Map<String, dynamic>> getCapacityReport({required String startDate, required String endDate}) async {
+    final response = await _dio.get(
+      '/api/v1/reports/capacity',
+      queryParameters: {
+        'start_date': startDate,
+        'end_date': endDate,
+      },
+    );
+    return response.data as Map<String, dynamic>;
+  }
+
+  Future<Map<String, dynamic>> getTimesheetPeriods({String? status, String? startDate, String? endDate}) async {
+    final queryParams = <String, dynamic>{};
+    if (status != null) queryParams['status'] = status;
+    if (startDate != null) queryParams['start_date'] = startDate;
+    if (endDate != null) queryParams['end_date'] = endDate;
+    final response = await _dio.get('/api/v1/timesheet-periods', queryParameters: queryParams);
+    return response.data as Map<String, dynamic>;
+  }
+
+  Future<Map<String, dynamic>> submitTimesheetPeriod(int periodId) async {
+    final response = await _dio.post('/api/v1/timesheet-periods/$periodId/submit');
+    return response.data as Map<String, dynamic>;
+  }
+
+  Future<Map<String, dynamic>> approveTimesheetPeriod(int periodId, {String? comment}) async {
+    final data = <String, dynamic>{};
+    if (comment != null && comment.trim().isNotEmpty) data['comment'] = comment.trim();
+    final response = await _dio.post('/api/v1/timesheet-periods/$periodId/approve', data: data);
+    return response.data as Map<String, dynamic>;
+  }
+
+  Future<Map<String, dynamic>> rejectTimesheetPeriod(int periodId, {String? reason}) async {
+    final data = <String, dynamic>{};
+    if (reason != null && reason.trim().isNotEmpty) data['reason'] = reason.trim();
+    final response = await _dio.post('/api/v1/timesheet-periods/$periodId/reject', data: data);
+    return response.data as Map<String, dynamic>;
+  }
+
+  Future<Map<String, dynamic>> getLeaveTypes() async {
+    final response = await _dio.get('/api/v1/time-off/leave-types');
+    return response.data as Map<String, dynamic>;
+  }
+
+  Future<Map<String, dynamic>> getTimeOffRequests({
+    String? status,
+    String? startDate,
+    String? endDate,
+  }) async {
+    final queryParams = <String, dynamic>{};
+    if (status != null) queryParams['status'] = status;
+    if (startDate != null) queryParams['start_date'] = startDate;
+    if (endDate != null) queryParams['end_date'] = endDate;
+    final response = await _dio.get('/api/v1/time-off/requests', queryParameters: queryParams);
+    return response.data as Map<String, dynamic>;
+  }
+
+  Future<Map<String, dynamic>> createTimeOffRequest({
+    required int leaveTypeId,
+    required String startDate,
+    required String endDate,
+    double? requestedHours,
+    String? comment,
+    bool submit = true,
+  }) async {
+    final data = <String, dynamic>{
+      'leave_type_id': leaveTypeId,
+      'start_date': startDate,
+      'end_date': endDate,
+      'submit': submit,
+    };
+    if (requestedHours != null) data['requested_hours'] = requestedHours;
+    if (comment != null && comment.trim().isNotEmpty) data['comment'] = comment.trim();
+    final response = await _dio.post('/api/v1/time-off/requests', data: data);
+    return response.data as Map<String, dynamic>;
+  }
+
+  Future<Map<String, dynamic>> getTimeOffBalances({int? userId}) async {
+    final queryParams = <String, dynamic>{};
+    if (userId != null) queryParams['user_id'] = userId;
+    final response = await _dio.get('/api/v1/time-off/balances', queryParameters: queryParams);
+    return response.data as Map<String, dynamic>;
+  }
+
+  Future<Map<String, dynamic>> approveTimeOffRequest(int requestId, {String? comment}) async {
+    final data = <String, dynamic>{};
+    if (comment != null && comment.trim().isNotEmpty) data['comment'] = comment.trim();
+    final response = await _dio.post('/api/v1/time-off/requests/$requestId/approve', data: data);
+    return response.data as Map<String, dynamic>;
+  }
+
+  Future<Map<String, dynamic>> rejectTimeOffRequest(int requestId, {String? comment}) async {
+    final data = <String, dynamic>{};
+    if (comment != null && comment.trim().isNotEmpty) data['comment'] = comment.trim();
+    final response = await _dio.post('/api/v1/time-off/requests/$requestId/reject', data: data);
+    return response.data as Map<String, dynamic>;
+  }
 }

mobile/lib/presentation/providers/finance_workforce_providers.dart

@@ -0,0 +1,76 @@
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:timetracker_mobile/presentation/providers/api_provider.dart';
+
+/// Date range for capacity/periods (current week)
+({String start, String end}) _weekRange() {
+  final now = DateTime.now();
+  final start = DateTime(now.year, now.month, now.day - now.weekday + 1);
+  final end = start.add(const Duration(days: 6));
+  return (start: start.toIso8601String().split('T')[0], end: end.toIso8601String().split('T')[0]);
+}
+
+final financeInvoicesProvider = FutureProvider.family<Map<String, dynamic>, int>((ref, page) async {
+  final client = await ref.watch(apiClientProvider.future);
+  if (client == null) return {'invoices': <Map<String, dynamic>>[], 'pagination': {'page': 1, 'pages': 1}};
+  return client.getInvoices(page: page, perPage: 20);
+});
+
+final financeExpensesProvider = FutureProvider.family<Map<String, dynamic>, int>((ref, page) async {
+  final client = await ref.watch(apiClientProvider.future);
+  if (client == null) return {'expenses': <Map<String, dynamic>>[], 'pagination': {'page': 1, 'pages': 1}};
+  return client.getExpenses(page: page, perPage: 20);
+});
+
+final timesheetPeriodsProvider = FutureProvider<Map<String, dynamic>>((ref) async {
+  final client = await ref.watch(apiClientProvider.future);
+  if (client == null) return {'timesheet_periods': <Map<String, dynamic>>[]};
+  final range = _weekRange();
+  return client.getTimesheetPeriods(startDate: range.start, endDate: range.end);
+});
+
+final capacityReportProvider = FutureProvider<Map<String, dynamic>>((ref) async {
+  final client = await ref.watch(apiClientProvider.future);
+  if (client == null) return {'capacity': <Map<String, dynamic>>[]};
+  final range = _weekRange();
+  return client.getCapacityReport(startDate: range.start, endDate: range.end);
+});
+
+final timeOffRequestsProvider = FutureProvider<Map<String, dynamic>>((ref) async {
+  final client = await ref.watch(apiClientProvider.future);
+  if (client == null) return {'time_off_requests': <Map<String, dynamic>>[]};
+  return client.getTimeOffRequests();
+});
+
+final leaveBalancesProvider = FutureProvider<Map<String, dynamic>>((ref) async {
+  final client = await ref.watch(apiClientProvider.future);
+  if (client == null) return {'balances': <Map<String, dynamic>>[]};
+  return client.getTimeOffBalances();
+});
+
+final leaveTypesProvider = FutureProvider<Map<String, dynamic>>((ref) async {
+  final client = await ref.watch(apiClientProvider.future);
+  if (client == null) return {'leave_types': <Map<String, dynamic>>[]};
+  return client.getLeaveTypes();
+});
+
+final financeProjectsProvider = FutureProvider<Map<String, dynamic>>((ref) async {
+  final client = await ref.watch(apiClientProvider.future);
+  if (client == null) return {'projects': <Map<String, dynamic>>[]};
+  return client.getProjects(status: 'active', perPage: 100);
+});
+
+final financeClientsProvider = FutureProvider<Map<String, dynamic>>((ref) async {
+  final client = await ref.watch(apiClientProvider.future);
+  if (client == null) return {'clients': <Map<String, dynamic>>[]};
+  return client.getClients(status: 'active', perPage: 100);
+});
+
+/// Whether the current user can approve timesheets / time-off
+final userCanApproveProvider = FutureProvider<bool>((ref) async {
+  final client = await ref.watch(apiClientProvider.future);
+  if (client == null) return false;
+  final me = await client.getUsersMe();
+  final user = me['user'] is Map<String, dynamic> ? me['user'] as Map<String, dynamic> : <String, dynamic>{};
+  final role = (user['role'] ?? '').toString().toLowerCase();
+  return (user['is_admin'] == true) || (role == 'admin' || role == 'owner' || role == 'manager' || role == 'approver');
+});

mobile/lib/presentation/screens/home_screen.dart

@@ -12,6 +12,7 @@ import 'timer_screen.dart';
 import 'projects_screen.dart';
 import 'time_entries_screen.dart';
 import 'settings_screen.dart';
+import 'finance_workforce_screen.dart';
 import 'dart:async';
 
 class HomeScreen extends StatefulWidget {
@@ -28,13 +29,17 @@ class _HomeScreenState extends State<HomeScreen> {
     const DashboardTab(),
     const ProjectsScreen(),
     const TimeEntriesScreen(),
+    const FinanceWorkforceScreen(),
     const SettingsScreen(),
   ];
 
   @override
   Widget build(BuildContext context) {
     return Scaffold(
-      body: _screens[_currentIndex],
+      body: IndexedStack(
+        index: _currentIndex,
+        children: _screens,
+      ),
       bottomNavigationBar: NavigationBar(
         selectedIndex: _currentIndex,
         onDestinationSelected: (index) {
@@ -58,6 +63,11 @@ class _HomeScreenState extends State<HomeScreen> {
             selectedIcon: Icon(Icons.history),
             label: 'Entries',
           ),
+          NavigationDestination(
+            icon: Icon(Icons.account_balance_wallet_outlined),
+            selectedIcon: Icon(Icons.account_balance_wallet),
+            label: 'Finance',
+          ),
           NavigationDestination(
             icon: Icon(Icons.settings_outlined),
             selectedIcon: Icon(Icons.settings),