feat(engine): 实现行动点系统

- 扩展 AgentState 添加 action_points, max_action_points, last_action_tick 字段
- 新增 ActionFeedback 模型用于返回行动执行结果
- 创建 action_points.py 模块实现行动点消耗与恢复逻辑
- 行动消耗表: vote=1, trigger_skill=2, influence=2, comment/support/chaos=0
- 每 tick 恢复 1 点行动点（不超过 max）
- 行动点不足时拒绝执行并返回失败反馈
- 新增 7 个测试用例，全部 37 个测试通过

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

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

engine-python/app/action_points.py

@@ -0,0 +1,89 @@
+"""行动点系统 - 管理用户行动点的消耗与恢复"""
+from typing import List, Tuple, Dict
+from .models import WorldState, Event, ActionFeedback
+
+# 行动消耗表
+ACTION_COST: Dict[str, int] = {
+    "vote": 1,
+    "trigger_skill": 2,
+    "influence": 2,
+    "comment": 0,
+    "support": 0,
+    "chaos": 0,
+}
+DEFAULT_COST = 0
+
+
+def get_action_cost(event_type: str) -> int:
+    """获取行动消耗的点数"""
+    return ACTION_COST.get(event_type, DEFAULT_COST)
+
+
+def check_action_points(state: WorldState, user: str, cost: int) -> bool:
+    """检查用户是否有足够的行动点"""
+    if user not in state.agents:
+        return True  # 非 agent 用户不受限制
+    return state.agents[user].action_points >= cost
+
+
+def consume_action_points(
+    state: WorldState, user: str, cost: int
+) -> None:
+    """消耗行动点"""
+    if user not in state.agents:
+        return
+    agent = state.agents[user]
+    agent.action_points = max(0, agent.action_points - cost)
+    agent.last_action_tick = state.tick
+
+
+def regenerate_action_points(state: WorldState) -> None:
+    """每 tick 恢复行动点"""
+    for agent_id, agent in state.agents.items():
+        if state.tick - agent.last_action_tick >= 1:
+            if agent.action_points < agent.max_action_points:
+                agent.action_points = min(
+                    agent.max_action_points,
+                    agent.action_points + 1
+                )
+
+
+def process_event_with_ap(
+    state: WorldState, event: Event
+) -> Tuple[bool, ActionFeedback]:
+    """处理单个事件的行动点检查
+
+    返回: (是否允许执行, 反馈信息)
+    """
+    user = event.user
+    cost = get_action_cost(event.type)
+
+    # 0 消耗的行动不需要检查
+    if cost == 0:
+        return True, ActionFeedback(
+            success=True,
+            reason="action applied",
+            remaining_ap=state.agents[user].action_points if user in state.agents else 0,
+            user=user
+        )
+
+    # 检查行动点
+    if not check_action_points(state, user, cost):
+        remaining = state.agents[user].action_points if user in state.agents else 0
+        return False, ActionFeedback(
+            success=False,
+            reason=f"insufficient action points (need {cost}, have {remaining})",
+            remaining_ap=remaining,
+            user=user
+        )
+
+    # 消耗行动点
+    consume_action_points(state, user, cost)
+    remaining = state.agents[user].action_points if user in state.agents else 0
+
+    return True, ActionFeedback(
+        success=True,
+        reason="action applied",
+        remaining_ap=remaining,
+        user=user
+    )