feat: AI Town MVP - 完整三层架构实现

- Python FastAPI 引擎：世界状态模拟、全局能量条、世界事件系统
- Node.js WebSocket 服务器：实时通信、事件队列批处理
- 前端仪表盘：世界状态可视化、行动日志、事件展示

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

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

engine-python/app/state.py

@@ -0,0 +1,35 @@
+import json
+from pathlib import Path
+from .models import WorldState, AgentState, GlobalMeter
+
+STATE_FILE = Path(__file__).parent.parent / "state.json"
+
+
+def get_default_state() -> WorldState:
+    """创建默认的世界状态"""
+    return WorldState(
+        tick=0,
+        weather="sunny",
+        town_mood=0,
+        agents={
+            "alice": AgentState(emotion="calm", goal="探索小镇", memory=[]),
+            "bob": AgentState(emotion="calm", goal="与人交流", memory=[]),
+        },
+        events=[],
+        global_meter=GlobalMeter(value=0, threshold=100, cooldown=0),
+    )
+
+
+def load_state() -> WorldState:
+    """从文件加载状态，如果不存在则创建默认状态"""
+    if STATE_FILE.exists():
+        with open(STATE_FILE, "r", encoding="utf-8") as f:
+            data = json.load(f)
+            return WorldState(**data)
+    return get_default_state()
+
+
+def save_state(state: WorldState) -> None:
+    """保存状态到文件"""
+    with open(STATE_FILE, "w", encoding="utf-8") as f:
+        json.dump(state.model_dump(), f, ensure_ascii=False, indent=2)