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。

admin/dashboard/server.py

@@ -50,6 +50,8 @@ class DashboardServer:
             self.system_job_loader = robot_instance.system_job_loader
             self.plugin_schedule_db = robot_instance.plugin_schedule_db
             self.plugin_schedule_manager = robot_instance.plugin_schedule_manager
+            self.group_plugin_config_db = robot_instance.group_plugin_config_db
+            self.group_plugin_config_service = robot_instance.group_plugin_config_service
             # 获取联系人管理器实例
             self.contact_manager = robot_instance.contact_manager
             self.plugin_manager = robot_instance.plugin_manager
@@ -154,6 +156,7 @@ class DashboardServer:
         from admin.dashboard.blueprints.friend_circle import friend_circle_bp
         from admin.dashboard.blueprints.system_jobs import system_jobs_bp
         from admin.dashboard.blueprints.plugin_schedules import plugin_schedules_bp
+        from admin.dashboard.blueprints.group_plugin_config import group_plugin_config_bp
 
         # 在app.register_blueprint部分添加
         app.register_blueprint(virtual_group_bp, url_prefix='/virtual_group')
@@ -170,6 +173,7 @@ class DashboardServer:
         app.register_blueprint(friend_circle_bp)
         app.register_blueprint(system_jobs_bp)
         app.register_blueprint(plugin_schedules_bp)
+        app.register_blueprint(group_plugin_config_bp)
 
         self.LOG.info("所有蓝图已注册")