feat(sprint-13.C mobile 2026-04-25): feature reporting (rapports trimestriels Contrôleur Interne)

Mobile mirror du backend P2-NEW-3. DRY strict — Clean Architecture identique aux autres features (compliance, devise).

Domain
- StatutRapport enum (draft, signe, archive, inconnu) + extension StatutRapportX (code/libelle/severite/fromCode)
- RapportTrimestriel entity (Equatable) + helpers libellePeriode, scoreSeverite (>=80 success, >=60 warning, <60 danger)

Data
- RapportTrimestrielModel.fromJson (parsing tolérant null + dates ISO)
- ReportingRemoteDataSourceImpl (Dio) : lister/generer/signer/archiver/telechargerPdf
- ReportingRepositoryImpl @Injectable

Presentation
- ReportingBloc : Load/Generer/Signer/Archiver events, 4 states (Initial/Loading/Loaded/Error)
- RapportsTrimestrielsPage : Material 3 ListView avec cards (period, score coloré, tag statut, hash tronqué) + EmptyView + ErrorView

Tests (10/10 verts)
- StatutRapportX × 2 (fromCode parse/null/inconnu, libelle/severite/code)
- RapportTrimestriel × 5 (libellePeriode, estDraft/estSigne/estArchive, scoreSeverite × 3)
- RapportTrimestrielModel.fromJson × 3 (complet, fallbacks, date invalide)

Note : viewer PDF interne reporté à un sprint dédié (intégration pdfx + permission storage Android). Téléchargement bytes via API exposé dans datasource pour usage futur.

lib/features/reporting/domain/entities/rapport_trimestriel.dart

@@ -0,0 +1,83 @@
+import 'package:equatable/equatable.dart';
+
+/// Statut d'un rapport trimestriel Contrôleur Interne.
+enum StatutRapport { draft, signe, archive, inconnu }
+
+extension StatutRapportX on StatutRapport {
+  String get code => switch (this) {
+        StatutRapport.draft => 'DRAFT',
+        StatutRapport.signe => 'SIGNE',
+        StatutRapport.archive => 'ARCHIVE',
+        StatutRapport.inconnu => '',
+      };
+
+  String get libelle => switch (this) {
+        StatutRapport.draft => 'Brouillon',
+        StatutRapport.signe => 'Signé',
+        StatutRapport.archive => 'Archivé',
+        StatutRapport.inconnu => 'Inconnu',
+      };
+
+  /// Couleur sémantique Material 3.
+  String get severite => switch (this) {
+        StatutRapport.draft => 'warning',
+        StatutRapport.signe => 'info',
+        StatutRapport.archive => 'success',
+        StatutRapport.inconnu => 'secondary',
+      };
+
+  static StatutRapport fromCode(String? code) {
+    return switch (code) {
+      'DRAFT' => StatutRapport.draft,
+      'SIGNE' => StatutRapport.signe,
+      'ARCHIVE' => StatutRapport.archive,
+      _ => StatutRapport.inconnu,
+    };
+  }
+}
+
+/// Rapport trimestriel Contrôleur Interne (miroir mobile du backend P2-NEW-3).
+class RapportTrimestriel extends Equatable {
+  final String id;
+  final String organisationId;
+  final int annee;
+  final int trimestre;
+  final DateTime? dateGeneration;
+  final StatutRapport statut;
+  final int scoreConformite;
+  final String? signataireId;
+  final DateTime? dateSignature;
+  final String? hashSha256;
+
+  const RapportTrimestriel({
+    required this.id,
+    required this.organisationId,
+    required this.annee,
+    required this.trimestre,
+    required this.dateGeneration,
+    required this.statut,
+    required this.scoreConformite,
+    this.signataireId,
+    this.dateSignature,
+    this.hashSha256,
+  });
+
+  bool get estDraft => statut == StatutRapport.draft;
+  bool get estSigne => statut == StatutRapport.signe;
+  bool get estArchive => statut == StatutRapport.archive;
+
+  String get libellePeriode => 'T$trimestre / $annee';
+
+  /// Couleur sémantique du score (success >= 80, warning >= 60, danger < 60).
+  String get scoreSeverite {
+    if (scoreConformite >= 80) return 'success';
+    if (scoreConformite >= 60) return 'warning';
+    return 'danger';
+  }
+
+  @override
+  List<Object?> get props => [
+        id, organisationId, annee, trimestre, dateGeneration, statut,
+        scoreConformite, signataireId, dateSignature, hashSha256,
+      ];
+}