feat(cache): Add thread-safe Redis client and enable activity stats cache

- Add get_thread_safe_redis() function with thread-local storage and PID checking to prevent "Future attached to a different loop" errors in Celery thread and prefork pools
- Implement health_check_interval=30 to prevent stale connection errors after fork
- Uncomment and enable ActivityStatsCache module in cache/memory/__init__.py
- Uncomment ActivityStatsCache implementation in activity_stats_cache.py and update to use get_thread_safe_redis()
- Update interest_memory.py to use thread-safe Redis client
- Update write_tools.py to use thread-safe Redis client
- Remove redundant Chinese comments from aioRedis.py for cleaner code
- Ensures safe Redis operations across different execution contexts and Celery worker configurations

api/app/cache/memory/__init__.py

@@ -4,9 +4,9 @@ Memory 缓存模块
 提供记忆系统相关的缓存功能
 """
 from .interest_memory import InterestMemoryCache
-# from .activity_stats_cache import ActivityStatsCache
+from .activity_stats_cache import ActivityStatsCache
 
 __all__ = [
     "InterestMemoryCache",
-    # "ActivityStatsCache",
+    "ActivityStatsCache",
 ]