feat: Round 52 narrative systems improvements

P1-A: QuestManager.OnLoad Enum.TryParse failure warning (dev builds)
P1-B: SaveData.QuestState ObjectiveCompleted dict; BuildObjectiveCompleted
       helper; OnSave/OnLoad wiring (DataVersion 2→3)
P2-A: Quest start/complete timestamps (_startedAtUtc/_completedAtUtc dicts;
       StartedAtUtc/CompletedAtUtc in SaveData; AcceptQuest/CompleteQuest/
       OnSave/OnLoad wiring)
P2-B: DialogueManager pending queue Queue→List + priority-eviction on full
       (lowest-priority item evicted when higher-priority request arrives)
P2-C: NpcSO.localizationTable field; NpcSOEditor uses npc.localizationTable
       in TryResolveNameKey, PingLocalizationFile, and button label
P3-A: QuestSO.failConditions[] multi-fail array; Obsolete failCondition;
       DispatchEvent updates fail check to any-of-array logic with fallback
P3-B: QuestObjectiveSO.prerequisiteObjectiveId; DispatchEvent gates objective
       event routing behind prerequisite completed check
P3-C: IQuestEventPayload interface + StringQuestPayload struct; QuestObjectiveSO
       typed TryHandleEvent(IQuestEventPayload) overload; DispatchEvent string
       overload delegates to typed IQuestEventPayload overload

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Assets/_Game/Scripts/Quest/IQuestManager.cs

@@ -175,6 +175,34 @@ namespace BaseGames.Quest
         event Action<string, QuestStateEnum, QuestStateEnum> OnQuestStateChanged;
     }
 
+    // =========================================================================
+    //  IQuestEventPayload  ──  强类型事件载荷接口
+    // =========================================================================
+
+    /// <summary>
+    /// 任务事件载荷接口，用于 <see cref="QuestManager"/> 强类型 <c>DispatchEvent</c> 重载。
+    /// 实现此接口可在不修改 <see cref="QuestObjectiveSO.TryHandleEvent"/> 原有 string 签名的前提下，
+    /// 逐步迁移到类型安全的载荷传递。
+    /// </summary>
+    public interface IQuestEventPayload
+    {
+        /// <summary>以字符串形式返回载荷内容，兼容旧版 TryHandleEvent(string payload) 签名。</summary>
+        string AsString();
+    }
+
+    /// <summary>
+    /// 字符串载荷适配器。封装现有 string payload，使其可作为 <see cref="IQuestEventPayload"/> 传递。
+    /// 旧版 <c>DispatchEvent(QuestEventType, string)</c> 内部通过此结构透明转换，不破坏现有调用方。
+    /// </summary>
+    public readonly struct StringQuestPayload : IQuestEventPayload
+    {
+        private readonly string _value;
+        public StringQuestPayload(string value) => _value = value;
+        /// <inheritdoc/>
+        public string AsString() => _value;
+        public static implicit operator StringQuestPayload(string s) => new StringQuestPayload(s);
+    }
+
 #if UNITY_EDITOR || DEVELOPMENT_BUILD
     /// <summary>
     /// 任务调试接口（仅编辑器 / 开发构建可用）。