Enforce serialization constraints

analysis_options.yaml

@@ -1,11 +1,13 @@
 include: package:very_good_analysis/analysis_options.7.0.0.yaml
 analyzer:
   errors:
+    cast_nullable_to_non_nullable: ignore
     document_ignores: ignore
     lines_longer_than_80_chars: ignore
     no_runtimetype_tostring: ignore
     overridden_fields: ignore
     prefer_initializing_formals: ignore
+    require_trailing_commas: ignore
     unnecessary_null_checks: ignore
     unused_element: ignore
     use_super_parameters: ignore

lib/src/models/auth/permission.dart

@@ -1,5 +1,6 @@
 import 'package:equatable/equatable.dart';
 import 'package:json_annotation/json_annotation.dart';
+import 'package:meta/meta.dart';
 
 part 'permission.g.dart';
 
@@ -8,7 +9,14 @@ part 'permission.g.dart';
 ///
 /// Permissions follow the format `resource.action`.
 /// {@endtemplate}
-@JsonSerializable()
+
+@immutable
+@JsonSerializable(
+  fieldRename: FieldRename.snake,
+  explicitToJson: true,
+  includeIfNull: false,
+  checked: true,
+)
 class Permission extends Equatable {
   /// {@macro permission}
   const Permission({required this.name});

lib/src/models/auth/user.dart

@@ -1,14 +1,22 @@
 import 'package:equatable/equatable.dart';
 import 'package:ht_shared/src/models/auth/user_role.dart';
 import 'package:json_annotation/json_annotation.dart';
+import 'package:meta/meta.dart';
 
 part 'user.g.dart';
 
 /// Represents a user within the system.
 ///
 /// This model holds basic information about the user, including their
 /// unique identifier, email (if available), and their assigned [role].
-@JsonSerializable()
+
+@immutable
+@JsonSerializable(
+  fieldRename: FieldRename.snake,
+  explicitToJson: true,
+  includeIfNull: false,
+  checked: true,
+)
 class User extends Equatable {
   /// Creates a new [User] instance.
   ///
@@ -34,6 +42,7 @@ class User extends Equatable {
   final String? email;
 
   /// The role of the user.
+
   final UserRole role;
 
   /// The date and time the user account was created.

lib/src/models/core/feed_item_action.dart

@@ -1,10 +1,11 @@
 import 'package:equatable/equatable.dart';
 import 'package:ht_shared/ht_shared.dart' show FeedItem;
 import 'package:ht_shared/src/models/core/content_type.dart';
+import 'package:ht_shared/src/models/core/core.dart' show FeedItem;
 import 'package:ht_shared/src/models/core/feed_item.dart' show FeedItem;
 import 'package:ht_shared/src/models/models.dart' show FeedItem;
-// Removed redundant FeedItem imports
 import 'package:json_annotation/json_annotation.dart';
+import 'package:meta/meta.dart';
 
 part 'feed_item_action.g.dart';
 
@@ -15,7 +16,14 @@ part 'feed_item_action.g.dart';
 /// and defined within this library. This allows for exhaustive pattern
 /// matching in the UI layer.
 /// {@endtemplate}
-@JsonSerializable(createFactory: false)
+@immutable
+@JsonSerializable(
+  createFactory: false,
+  fieldRename: FieldRename.snake,
+  explicitToJson: true,
+  includeIfNull: false,
+  checked: true,
+)
 sealed class FeedItemAction extends Equatable {
   /// {@macro feed_item_action}
   const FeedItemAction({required this.type});
@@ -66,7 +74,13 @@ Map<String, dynamic> feedItemActionToJson(FeedItemAction action) {
 /// {@template open_internal_content}
 /// An action to open content that resides within the application.
 /// {@endtemplate}
-@JsonSerializable()
+@immutable
+@JsonSerializable(
+  fieldRename: FieldRename.snake,
+  explicitToJson: true,
+  includeIfNull: false,
+  checked: true,
+)
 class OpenInternalContent extends FeedItemAction {
   /// {@macro open_internal_content}
   const OpenInternalContent({
@@ -82,6 +96,7 @@ class OpenInternalContent extends FeedItemAction {
   final String contentId;
 
   /// The type of the internal content (e.g., headline, category, source).
+
   final ContentType contentType;
 
   @override
@@ -99,7 +114,13 @@ class OpenInternalContent extends FeedItemAction {
 /// {@template show_interstitial_then_open_internal_content}
 /// An action to show an interstitial advertisement, then open internal content.
 /// {@endtemplate}
-@JsonSerializable()
+@immutable
+@JsonSerializable(
+  fieldRename: FieldRename.snake,
+  explicitToJson: true,
+  includeIfNull: false,
+  checked: true,
+)
 class ShowInterstitialThenOpenInternalContent extends FeedItemAction {
   /// {@macro show_interstitial_then_open_internal_content}
   const ShowInterstitialThenOpenInternalContent({
@@ -118,6 +139,7 @@ class ShowInterstitialThenOpenInternalContent extends FeedItemAction {
   final String contentId;
 
   /// The type of the internal content (e.g., headline, category, source).
+
   final ContentType contentType;
 
   @override
@@ -134,7 +156,13 @@ class ShowInterstitialThenOpenInternalContent extends FeedItemAction {
 /// {@template open_external_url}
 /// An action to open an external URL, typically in a web browser.
 /// {@endtemplate}
-@JsonSerializable()
+@immutable
+@JsonSerializable(
+  fieldRename: FieldRename.snake,
+  explicitToJson: true,
+  includeIfNull: false,
+  checked: true,
+)
 class OpenExternalUrl extends FeedItemAction {
   /// {@macro open_external_url}
   const OpenExternalUrl({required this.url}) : super(type: 'open_external_url');

lib/src/models/entities/category.dart

@@ -14,7 +14,12 @@ part 'category.g.dart';
 /// The [id] is automatically generated using UUID v4 if not provided.
 /// {@endtemplate}
 @immutable
-@JsonSerializable(explicitToJson: true, includeIfNull: false)
+@JsonSerializable(
+  fieldRename: FieldRename.snake,
+  explicitToJson: true,
+  includeIfNull: false,
+  checked: true,
+)
 class Category extends FeedItem {
   /// {@macro category}
   ///

lib/src/models/entities/country.dart

@@ -2,6 +2,7 @@ import 'package:ht_shared/src/models/core/feed_item.dart';
 import 'package:ht_shared/src/models/core/feed_item_action.dart'
     show FeedItemAction, feedItemActionFromJson, feedItemActionToJson;
 import 'package:json_annotation/json_annotation.dart';
+import 'package:meta/meta.dart';
 import 'package:uuid/uuid.dart';
 
 part 'country.g.dart';
@@ -12,7 +13,13 @@ part 'country.g.dart';
 /// Used typically in contexts like selecting a country for news headlines
 /// or user profile settings.
 /// {@endtemplate}
-@JsonSerializable()
+@immutable
+@JsonSerializable(
+  fieldRename: FieldRename.snake,
+  explicitToJson: true,
+  includeIfNull: false,
+  checked: true,
+)
 class Country extends FeedItem {
   /// {@macro country}
   Country({