feat(features): refontes onboarding/organizations/profile/reports/settings/solidarity

- onboarding : datasource souscription, models formule/status, bloc complet
- organizations : bloc orgs + switcher + types bloc, models, pages edit/create
- profile : bloc complet avec change password, delete account, preferences
- reports : bloc avec DashboardReports + ScheduleReports + GenerateReport
- settings : language, privacy, feedback pages
- solidarity : bloc complet demandes d'aide (CRUD, approuver, rejeter)

lib/features/onboarding/presentation/pages/awaiting_validation_page.dart

@@ -3,6 +3,7 @@ import 'package:flutter/material.dart';
 import '../../data/models/souscription_status_model.dart';
 import '../../../../features/authentication/presentation/bloc/auth_bloc.dart';
 import '../../../../shared/design_system/tokens/unionflow_colors.dart';
+import '../../../../shared/design_system/tokens/app_colors.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
 
 /// Page de secours — affichée si l'auto-activation échoue après paiement.
@@ -55,7 +56,7 @@ class _AwaitingValidationPageState extends State<AwaitingValidationPage>
     final sosc = widget.souscription;
 
     return Scaffold(
-      backgroundColor: UnionFlowColors.background,
+      backgroundColor: Theme.of(context).scaffoldBackgroundColor,
       body: SafeArea(
         child: SingleChildScrollView(
           padding: const EdgeInsets.all(28),
@@ -199,7 +200,7 @@ class _AwaitingValidationPageState extends State<AwaitingValidationPage>
                   ),
                   style: ElevatedButton.styleFrom(
                     backgroundColor: UnionFlowColors.unionGreen,
-                    foregroundColor: Colors.white,
+                    foregroundColor: AppColors.onPrimary,
                     padding: const EdgeInsets.symmetric(vertical: 14),
                     shape: RoundedRectangleBorder(
                         borderRadius: BorderRadius.circular(14)),

lib/features/onboarding/presentation/pages/period_selection_page.dart

@@ -63,7 +63,7 @@ class _PeriodSelectionPageState extends State<PeriodSelectionPage> {
     final prixSelected = _estimerPrix(_selectedPeriode);
 
     return Scaffold(
-      backgroundColor: UnionFlowColors.background,
+      backgroundColor: Theme.of(context).scaffoldBackgroundColor,
       body: Column(
         children: [
           OnboardingStepHeader(