feat: implement base architecture and core repositories for weapon tracking and target analysis functionality

lib/data/models/maintenance.dart

@@ -0,0 +1,57 @@
+enum MaintenanceType {
+  cleaning('Nettoyage'),
+  repair('Réparation'),
+  inspection('Inspection'),
+  upgrade('Amélioration'),
+  other('Autre');
+
+  final String displayName;
+  const MaintenanceType(this.displayName);
+
+  static MaintenanceType fromString(String value) {
+    return MaintenanceType.values.firstWhere(
+      (type) => type.name == value,
+      orElse: () => MaintenanceType.other,
+    );
+  }
+}
+
+class MaintenanceEntry {
+  final String id;
+  final String weaponId;
+  final MaintenanceType type;
+  final String description;
+  final DateTime date;
+  final int? roundsSinceLastMaintenance;
+
+  MaintenanceEntry({
+    required this.id,
+    required this.weaponId,
+    required this.type,
+    required this.description,
+    required this.date,
+    this.roundsSinceLastMaintenance,
+  });
+
+  Map<String, dynamic> toMap() {
+    return {
+      'id': id,
+      'weapon_id': weaponId,
+      'type': type.name,
+      'description': description,
+      'date': date.toIso8601String(),
+      'rounds_since_last': roundsSinceLastMaintenance,
+    };
+  }
+
+  factory MaintenanceEntry.fromMap(Map<String, dynamic> map) {
+    return MaintenanceEntry(
+      id: map['id'] as String,
+      weaponId: map['weapon_id'] as String,
+      type: MaintenanceType.fromString(map['type'] as String),
+      description: map['description'] as String,
+      date: DateTime.parse(map['date'] as String),
+      roundsSinceLastMaintenance: map['rounds_since_last'] as int?,
+    );
+  }
+}