优化：Redis 连接增强 — TCP keepalive 适配 + 截图处理器独立重连

- 新增 _build_keepalive_options() 适配 Linux/Windows TCP keepalive
- health_check_interval 30→15秒，更快发现断连
- 截图处理器新增 _reconnect_cloud_redis() 独立重连能力
- 截图监听捕获 ConnectionError 主动重连，不再退避到60秒

core/screenshot_handler.py

@@ -16,6 +16,7 @@ from typing import Optional
 
 import cv2
 import numpy as np
+import redis
 import requests
 
 from config.settings import get_settings, COSConfig
@@ -121,6 +122,32 @@ class ScreenshotHandler:
             else:
                 logger.error("[截图] 创建 consumer group 失败: %s", e)
 
+    # ==================== 重连 ====================
+
+    def _reconnect_cloud_redis(self):
+        """重建云端 Redis 连接"""
+        try:
+            from core.config_sync import _build_keepalive_options
+            cfg = self._settings.cloud_redis
+            self._cloud_redis = redis.Redis(
+                host=cfg.host,
+                port=cfg.port,
+                db=cfg.db,
+                password=cfg.password,
+                decode_responses=cfg.decode_responses,
+                socket_connect_timeout=5,
+                socket_timeout=10,
+                retry_on_timeout=True,
+                socket_keepalive=True,
+                socket_keepalive_options=_build_keepalive_options(),
+                health_check_interval=15,
+            )
+            self._cloud_redis.ping()
+            logger.info("[截图] 云端 Redis 重连成功")
+        except Exception as e:
+            logger.warning("[截图] 云端 Redis 重连失败: %s", e)
+            self._cloud_redis = None
+
     # ==================== 主循环 ====================
 
     def _listen_loop(self):
@@ -157,6 +184,14 @@ class ScreenshotHandler:
                             except Exception:
                                 pass
 
+            except redis.ConnectionError as e:
+                if self._stop_event.is_set():
+                    return
+                logger.warning("[截图] 云端 Redis 连接断开: %s, %ds 后重连...", e, backoff)
+                self._reconnect_cloud_redis()
+                self._stop_event.wait(backoff)
+                backoff = min(backoff * 2, max_backoff)
+
             except Exception as e:
                 if self._stop_event.is_set():
                     return