feat: AI虚拟用户新闻互动系统 v1.3.0 初始提交

- 虚拟用户管理（昵称/头像/性别/简介/邮箱同步到目标平台）
- AI互动调度（点赞/收藏/评论/转发）
- 日志时间改为北京时间
- 评论达上限后继续执行点赞收藏转发
- 一键登出全部功能
- 浅色主题UI

backend/app/core/redis_client.py

@@ -0,0 +1,81 @@
+"""Redis缓存客户端"""
+import json
+import redis.asyncio as aioredis
+from app.core.config import settings
+from app.core.logger import logger
+
+_redis_client = None
+
+
+async def get_redis() -> aioredis.Redis:
+    global _redis_client
+    if _redis_client is None:
+        _redis_client = aioredis.from_url(
+            f"redis://{settings.REDIS_HOST}:{settings.REDIS_PORT}",
+            encoding="utf-8",
+            decode_responses=True,
+        )
+    return _redis_client
+
+
+# Session键前缀
+SESSION_PREFIX = "session:"
+LOCK_PREFIX = "lock:"
+RATE_PREFIX = "rate:"
+
+
+async def set_session(user_id: int, session_data: dict, expire: int = 86400):
+    """存储用户会话"""
+    r = await get_redis()
+    key = f"{SESSION_PREFIX}{user_id}"
+    await r.setex(key, expire, json.dumps(session_data, ensure_ascii=False))
+
+
+async def get_session(user_id: int) -> dict | None:
+    """获取用户会话"""
+    r = await get_redis()
+    key = f"{SESSION_PREFIX}{user_id}"
+    data = await r.get(key)
+    if data:
+        return json.loads(data)
+    return None
+
+
+async def delete_session(user_id: int):
+    """删除用户会话"""
+    r = await get_redis()
+    key = f"{SESSION_PREFIX}{user_id}"
+    await r.delete(key)
+
+
+async def acquire_lock(name: str, expire: int = 60) -> bool:
+    """获取分布式锁"""
+    r = await get_redis()
+    key = f"{LOCK_PREFIX}{name}"
+    result = await r.set(key, "1", nx=True, ex=expire)
+    return result is True
+
+
+async def release_lock(name: str):
+    """释放分布式锁"""
+    r = await get_redis()
+    key = f"{LOCK_PREFIX}{name}"
+    await r.delete(key)
+
+
+async def incr_rate(key: str, expire: int = 86400) -> int:
+    """限流计数"""
+    r = await get_redis()
+    rate_key = f"{RATE_PREFIX}{key}"
+    count = await r.incr(rate_key)
+    if count == 1:
+        await r.expire(rate_key, expire)
+    return count
+
+
+async def get_counter(key: str) -> int:
+    """获取计数"""
+    r = await get_redis()
+    rate_key = f"{RATE_PREFIX}{key}"
+    val = await r.get(rate_key)
+    return int(val) if val else 0