fix: 修复设置系统脱节、队列计数漂移、资源泄露等全量问题

- 统一设置系统：create_scheduler_service 读取 DB 设置覆盖默认值
- 修复 ProxyRepository.update_score 误删所有无效代理的 SQL
- ValidationQueue：修复 Worker 计数漂移与启动恢复任务饿死
- SchedulerService：移除 drain() 阻塞，主循环可正常响应 stop
- TaskService：在调度器周期内自动清理过期任务，防止内存泄漏
- lifespan/conftest：规范关闭顺序，消除 Event loop closed 警告
- Repository：异常日志增加 exc_info，今日新增按 created_at 统计
- ValidatorService：防止 HTTP session 重复关闭，移除 SOCKS 多余 close
- 前端：补全 pluginsStore.isEmpty，ProxyList 最低分数上限改为 100
- 删除 config.py 中冗余的 cors_origins_list property

app/services/task_service.py

@@ -0,0 +1,62 @@
+"""轻量级异步任务服务 - 内存存储，用于跟踪后台爬取任务"""
+import uuid
+from datetime import datetime, timedelta
+from typing import Optional, Dict, Any
+from app.core.log import logger
+
+
+class TaskService:
+    """异步任务状态管理器"""
+
+    def __init__(self, max_age_seconds: int = 3600):
+        self._tasks: Dict[str, dict] = {}
+        self._max_age_seconds = max_age_seconds
+
+    def create_task(self, task_type: str) -> str:
+        task_id = str(uuid.uuid4())
+        now = datetime.now()
+        self._tasks[task_id] = {
+            "id": task_id,
+            "type": task_type,
+            "status": "pending",
+            "message": "",
+            "data": {},
+            "created_at": now,
+            "updated_at": now,
+        }
+        return task_id
+
+    def update_task(
+        self,
+        task_id: str,
+        status: Optional[str] = None,
+        message: Optional[str] = None,
+        data: Optional[dict] = None,
+    ) -> bool:
+        task = self._tasks.get(task_id)
+        if not task:
+            return False
+        if status is not None:
+            task["status"] = status
+        if message is not None:
+            task["message"] = message
+        if data is not None:
+            task["data"].update(data)
+        task["updated_at"] = datetime.now()
+        return True
+
+    def get_task(self, task_id: str) -> Optional[dict]:
+        return self._tasks.get(task_id)
+
+    def cleanup_old_tasks(self) -> int:
+        cutoff = datetime.now() - timedelta(seconds=self._max_age_seconds)
+        to_remove = [tid for tid, task in self._tasks.items() if task["created_at"] < cutoff]
+        for tid in to_remove:
+            del self._tasks[tid]
+        if to_remove:
+            logger.info(f"TaskService cleaned up {len(to_remove)} old tasks")
+        return len(to_remove)
+
+
+# 全局任务服务实例
+task_service = TaskService()