feat(群级配置): 新增MySQL+Redis持久缓存并接入进群欢迎差异化配置

新增群级插件配置表与服务层，采用MySQL持久化+Redis长期缓存(TTL=-1)；后台新增群级插件配置管理页面与API，支持按群按插件维护JSON配置并在修改后同步回填MySQL和刷新Redis；已将群成员变更监控插件接入该配置，支持欢迎文案与卡片URL等按群差异化。

utils/group_plugin_config_service.py

@@ -0,0 +1,99 @@
+# -*- coding: utf-8 -*-
+import json
+from typing import Any, Dict, List, Optional
+
+from loguru import logger
+
+from db.group_plugin_config_db import GroupPluginConfigDBOperator
+
+
+class GroupPluginConfigService:
+    """群级插件配置服务（MySQL 持久化 + Redis 永久缓存）。"""
+
+    REDIS_KEY_PREFIX = "group:plugin:cfg"
+
+    def __init__(self, db_operator: GroupPluginConfigDBOperator, redis_client):
+        self.db = db_operator
+        self.redis = redis_client
+
+    @classmethod
+    def _build_cache_key(cls, group_id: str, plugin_name: str, config_key: str = "default") -> str:
+        return f"{cls.REDIS_KEY_PREFIX}:{group_id}:{plugin_name}:{config_key}"
+
+    def _write_cache(self, key: str, payload: Dict[str, Any]) -> None:
+        """写入 Redis 缓存（TTL=-1，永久有效）。"""
+        # 需求明确要求长期缓存，这里不设置过期时间，保持 TTL=-1。
+        self.redis.set(key, json.dumps(payload, ensure_ascii=False))
+
+    def _delete_cache(self, key: str) -> None:
+        """删除 Redis 缓存。"""
+        self.redis.delete(key)
+
+    def get_config(
+        self,
+        group_id: str,
+        plugin_name: str,
+        config_key: str = "default",
+        default: Optional[Dict[str, Any]] = None,
+    ) -> Dict[str, Any]:
+        """读取配置：先 Redis，未命中再查 MySQL 并回填 Redis。"""
+        cache_key = self._build_cache_key(group_id, plugin_name, config_key)
+        cached = self.redis.get(cache_key)
+        if cached:
+            try:
+                payload = json.loads(cached)
+                if isinstance(payload, dict):
+                    return payload
+            except Exception as e:
+                logger.warning(f"群插件配置缓存解析失败，将回源数据库: key={cache_key}, error={e}")
+
+        row = self.db.get_config(group_id, plugin_name, config_key)
+        if not row:
+            result = dict(default or {})
+            # 缓存空结果可减少热点穿透；后续后台更新会主动刷新。
+            self._write_cache(cache_key, result)
+            return result
+
+        result = row.get("config_json") or {}
+        if not isinstance(result, dict):
+            result = {}
+        self._write_cache(cache_key, result)
+        return result
+
+    def list_configs(self, group_id: str = "", plugin_name: str = "") -> List[Dict[str, Any]]:
+        """列出配置（后台展示用）。"""
+        return self.db.list_configs(group_id=group_id, plugin_name=plugin_name)
+
+    def upsert_config(
+        self,
+        group_id: str,
+        plugin_name: str,
+        config_data: Dict[str, Any],
+        config_key: str = "default",
+        enabled: bool = True,
+        updated_by: str = "system",
+    ) -> bool:
+        """写配置：先落 MySQL，再刷新 Redis。"""
+        ok = self.db.upsert_config(
+            group_id=group_id,
+            plugin_name=plugin_name,
+            config_key=config_key,
+            config_data=config_data or {},
+            enabled=enabled,
+            updated_by=updated_by,
+        )
+        if not ok:
+            return False
+
+        # 需求要求“修改后刷新 redis 内容”，这里直接回填最新值。
+        cache_key = self._build_cache_key(group_id, plugin_name, config_key)
+        self._write_cache(cache_key, config_data or {})
+        return True
+
+    def delete_config(self, group_id: str, plugin_name: str, config_key: str = "default") -> bool:
+        """删除配置：删 MySQL 后同步清理 Redis。"""
+        ok = self.db.delete_config(group_id, plugin_name, config_key)
+        if ok:
+            cache_key = self._build_cache_key(group_id, plugin_name, config_key)
+            self._delete_cache(cache_key)
+        return ok