feat: implement survival, crafting, memory, and social systems

- Phase 13: Autonomous Agency - agents now have actions and locations
- Phase 15: Sickness mechanics with immunity and weather effects
- Phase 16: Crafting system (medicine from herbs)
- Phase 17-A: Resource scarcity with tree fruit regeneration
- Phase 17-B: Social roles (leader, follower, loner) with clique behavior
- Phase 17-C: Random events support
- Add AgentMemory model for long-term agent memory storage
- Add memory_service for managing agent memories
- Update Unity client models and event handlers

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

unity-client/Assets/Scripts/EventLog.cs

@@ -38,7 +38,6 @@ namespace TheIsland.UI
         private List<GameObject> _entries = new List<GameObject>();
         private bool _visible = true;
         private int _unread = 0;
-        private bool _ready = false;
 
         private void Awake()
         {
@@ -83,7 +82,6 @@ namespace TheIsland.UI
             if (NetworkManager.Instance != null)
             {
                 SubscribeEvents();
-                _ready = true;
                 AddLog("事件日志已就绪", Color.yellow);
                 Debug.Log("[EventLog] 初始化完成");
             }