feat: add SuggestedContentTemplate model

- Defines suggestion block config
- Includes type, display, content
- Supports title and description

Author: fulleni

lib/src/models/feed_extras/suggested_content_template.dart

@@ -0,0 +1,66 @@
+import 'package:equatable/equatable.dart';
+import 'package:ht_shared/src/models/core/content_type.dart';
+import 'package:ht_shared/src/models/feed_decorators/suggested_content_display_type.dart';
+import 'package:ht_shared/src/models/feed_extras/feed_template_types.dart';
+import 'package:json_annotation/json_annotation.dart';
+
+part 'suggested_content_template.g.dart';
+
+/// {@template suggested_content_template}
+/// Defines the static content and configuration for a suggestion block.
+/// The 'type' of an instance should match a [SuggestionTemplateType] value.
+/// {@endtemplate}
+@JsonSerializable(explicitToJson: true)
+class SuggestedContentTemplate extends Equatable {
+  /// {@macro suggested_content_template}
+  const SuggestedContentTemplate({
+    required this.type,
+    required this.displayType,
+    required this.suggestedContentType,
+    this.title,
+    this.description,
+    this.maxItemsToDisplay,
+    this.fetchCriteria,
+  });
+
+  /// Creates a [SuggestedContentTemplate] from JSON data.
+  factory SuggestedContentTemplate.fromJson(Map<String, dynamic> json) =>
+      _$SuggestedContentTemplateFromJson(json);
+
+  /// The type of suggestion template, matching a [SuggestionTemplateType] value.
+  final SuggestionTemplateType type;
+
+  /// An optional title for the suggestion block (e.g., "You might like...").
+  final String? title;
+
+  /// An optional description for the suggestion block.
+  final String? description;
+
+  /// The visual presentation or layout style for this suggestion block.
+  final SuggestedContentDisplayType displayType;
+
+  /// Defines what kind of primary content this suggestion block will contain
+  /// (e.g., if suggesting categories, this would be [ContentType.category]).
+  final ContentType suggestedContentType;
+
+  /// Maximum number of items to display within this suggestion block.
+  final int? maxItemsToDisplay;
+
+  /// Criteria for fetching dynamic items, e.g., "popular", "newest".
+  /// This is a simple string; the decorator will interpret it.
+  final String? fetchCriteria;
+
+  /// Converts this [SuggestedContentTemplate] instance to JSON data.
+  Map<String, dynamic> toJson() => _$SuggestedContentTemplateToJson(this);
+
+  @override
+  List<Object?> get props => [
+        type,
+        title,
+        description,
+        displayType,
+        suggestedContentType,
+        maxItemsToDisplay,
+        fetchCriteria,
+      ];
+}