feat(chat): implement boredom cooldown mechanism

Add last_boredom_trigger_time tracking to adjust boredom threshold
dynamically between 25 and 50 based on recent trigger history.
Prevents frequent boredom state transitions by increasing threshold
when boredom was recently triggered. Set timestamp when boredom
processing begins.

Author: This-is-XiaoDeng

src/plugins/nonebot_plugin_chat/core/main_session.py

@@ -87,6 +87,7 @@ def __init__(self, last_activate_time: datetime, lang_str: str = "zh_hans") -> N
         self.state = StateEnum.ACTIVATE
         self.status_manager = StatusManager()
         self.state_until = None
+        self.last_boredom_trigger_time = None
         # 记录当前正在执行的动作，用于后续更新状态
         self._current_action_start_time: Optional[datetime] = None
         self._current_action_sleep_plan_end: Optional[datetime] = None
@@ -99,12 +100,17 @@ async def process_timer(self) -> None:
 
             case StateEnum.ACTIVATE:
                 self.boredom += 1
-                if self.boredom >= 25 and self.status_manager.set_mood(MoodEnum.BORED)[0]:
+                if self.last_boredom_trigger_time and datetime.now() - self.last_boredom_trigger_time: 
+                    threshold = 50
+                else:
+                    threshold = 25
+                if self.boredom >= threshold:
                     self.state = StateEnum.BORED
                     self.boredom = 0.0
 
             case StateEnum.BORED:
                 asyncio.create_task(self.process_boredom())
+                
 
         if self.state_until is not None and datetime.now() > self.state_until:
             # 如果当前是 SLEEPING 状态且是正常结束（没有被 wake_up 提前处理），更新状态
@@ -235,6 +241,7 @@ async def process_boredom(self) -> None:
         if self.boredom_processor_lock.locked():
             return
         async with self.boredom_processor_lock:
+            self.last_boredom_trigger_time = datetime.now()
             fetcher = await MessageFetcher.create(
                 [
                     generate_message(await self.generate_system_prompt(), "system"),