docs: 更新协议文档，删除废弃计划文档

- 更新 http-error-codes, user-points-chat-data-protocol
- 更新 divination-run-protocol, profile-protocol
- 删除废弃的后端和前端设计计划文档

apps/lib/features/divination/data/models/divination_backend_models.dart

@@ -52,6 +52,7 @@ class RunAcceptedData {
 
 class DivinationRunAggregate {
   const DivinationRunAggregate({
+    this.threadId,
     required this.derived,
     required this.signLevel,
     required this.conclusion,
@@ -62,6 +63,7 @@ class DivinationRunAggregate {
   });
 
   final DerivedDivinationData derived;
+  final String? threadId;
   final String signLevel;
   final List<String> conclusion;
   final List<String> focusPoints;
@@ -72,6 +74,7 @@ class DivinationRunAggregate {
   DivinationResultData toViewData(DivinationParams params) {
     return DivinationResultData(
       params: params,
+      threadId: threadId,
       binaryCode: derived.binaryCode,
       changedBinaryCode: derived.changedBinaryCode,
       guaName: derived.guaName,

apps/lib/features/divination/data/models/divination_result.dart

@@ -2,6 +2,7 @@ import 'divination_params.dart';
 
 class DivinationResultData {
   const DivinationResultData({
+    this.threadId,
     required this.params,
     required this.binaryCode,
     required this.changedBinaryCode,
@@ -22,6 +23,7 @@ class DivinationResultData {
   });
 
   final DivinationParams params;
+  final String? threadId;
   final String binaryCode;
   final String changedBinaryCode;
   final String guaName;
@@ -44,6 +46,7 @@ class DivinationResultData {
   Map<String, dynamic> toJson() {
     return <String, dynamic>{
       'params': params.toPayload(),
+      'threadId': threadId,
       'binaryCode': binaryCode,
       'changedBinaryCode': changedBinaryCode,
       'guaName': guaName,
@@ -81,6 +84,7 @@ class DivinationResultData {
 
     return DivinationResultData(
       params: DivinationParams.fromPayload(paramsRaw),
+      threadId: json['threadId'] as String?,
       binaryCode: _requiredString(json, 'binaryCode'),
       changedBinaryCode: _requiredString(json, 'changedBinaryCode'),
       guaName: _requiredString(json, 'guaName'),

apps/lib/features/divination/data/models/follow_up_message.dart

@@ -0,0 +1,52 @@
+class FollowUpMessage {
+  const FollowUpMessage({
+    required this.id,
+    required this.seq,
+    required this.role,
+    required this.content,
+    required this.timestamp,
+  });
+
+  final String id;
+  final int seq;
+  final String role;
+  final String content;
+  final DateTime timestamp;
+
+  factory FollowUpMessage.fromJson(Map<String, dynamic> json) {
+    return FollowUpMessage(
+      id: _requiredString(json, 'id'),
+      seq: _requiredInt(json, 'seq'),
+      role: _requiredString(json, 'role'),
+      content: _requiredStringAllowEmpty(json, 'content'),
+      timestamp: DateTime.parse(_requiredString(json, 'timestamp')).toLocal(),
+    );
+  }
+}
+
+String _requiredString(Map<String, dynamic> json, String key) {
+  final value = json[key];
+  if (value is! String || value.isEmpty) {
+    throw FormatException('Missing required string: $key');
+  }
+  return value;
+}
+
+String _requiredStringAllowEmpty(Map<String, dynamic> json, String key) {
+  final value = json[key];
+  if (value is! String) {
+    throw FormatException('Missing required string: $key');
+  }
+  return value;
+}
+
+int _requiredInt(Map<String, dynamic> json, String key) {
+  final value = json[key];
+  if (value is int) {
+    return value;
+  }
+  if (value is num) {
+    return value.toInt();
+  }
+  throw FormatException('Missing required int: $key');
+}