fix: resolve flutter analyze errors - remove leaked code, fix method calls, cleanup imports

lib/core/models/chapter_model.dart

@@ -0,0 +1,88 @@
+import 'package:equatable/equatable.dart';
+
+class ChapterModel extends Equatable {
+  const ChapterModel({
+    required this.id,
+    required this.novelId,
+    required this.number,
+    required this.title,
+    required this.content,
+    this.views = 0,
+    this.volumeNumber,
+    this.volumeTitle,
+    this.volumeChapterNumber,
+    this.prevChapterId,
+    this.prevChapterNumber,
+    this.nextChapterId,
+    this.nextChapterNumber,
+    required this.createdAt,
+  });
+
+  final String id;
+  final String novelId;
+  final int number;
+  final String title;
+  final String content;
+  final int views;
+  final int? volumeNumber;
+  final String? volumeTitle;
+  final int? volumeChapterNumber;
+  final String? prevChapterId;
+  final int? prevChapterNumber;
+  final String? nextChapterId;
+  final int? nextChapterNumber;
+  final DateTime createdAt;
+
+  factory ChapterModel.fromJson(Map<String, dynamic> json) => ChapterModel(
+        id: json['id'] as String,
+        novelId: json['novelId'] as String,
+        number: (json['number'] as num).toInt(),
+        title: json['title'] as String,
+        content: json['content'] as String,
+        views: (json['views'] as num?)?.toInt() ?? 0,
+        volumeNumber: json['volumeNumber'] as int?,
+        volumeTitle: json['volumeTitle'] as String?,
+        volumeChapterNumber: json['volumeChapterNumber'] as int?,
+        prevChapterId: json['prevChapterId'] as String?,
+        prevChapterNumber: json['prevChapterNumber'] as int?,
+        nextChapterId: json['nextChapterId'] as String?,
+        nextChapterNumber: json['nextChapterNumber'] as int?,
+        createdAt: DateTime.parse(json['createdAt'] as String),
+      );
+
+  @override
+  List<Object?> get props => [id, number];
+}
+
+class ChapterListItem extends Equatable {
+  const ChapterListItem({
+    required this.id,
+    required this.number,
+    required this.title,
+    this.volumeNumber,
+    this.volumeTitle,
+    this.volumeChapterNumber,
+    required this.createdAt,
+  });
+
+  final String id;
+  final int number;
+  final String title;
+  final int? volumeNumber;
+  final String? volumeTitle;
+  final int? volumeChapterNumber;
+  final DateTime createdAt;
+
+  factory ChapterListItem.fromJson(Map<String, dynamic> json) => ChapterListItem(
+        id: json['id'] as String,
+        number: (json['number'] as num).toInt(),
+        title: json['title'] as String,
+        volumeNumber: json['volumeNumber'] as int?,
+        volumeTitle: json['volumeTitle'] as String?,
+        volumeChapterNumber: json['volumeChapterNumber'] as int?,
+        createdAt: DateTime.parse(json['createdAt'] as String),
+      );
+
+  @override
+  List<Object?> get props => [id, number];
+}