feat：- add sql

电子日历/app-im.sql

+-- 用户设备IM
+-- 用户设备IM
+CREATE TABLE `t_user_device_im` (
+  `id` bigint NOT NULL,
+  `user_id` bigint NOT NULL COMMENT '用户ID',
+  `device_id` bigint NOT NULL COMMENT '设备ID',
+  `im_id` varchar(100) NOT NULL COMMENT 'IM用户ID',
+  `created_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间',
+  `updated_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '更新时间',
+  PRIMARY KEY (`id`)
+) ENGINE=InnoDB  DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci COMMENT='用户设备IM';
+
+CREATE INDEX idx_user_id_device_id ON t_user_device_im(user_id, device_id);
+
+CREATE INDEX idx_device_id ON t_user_device_im(device_id);
+
+CREATE INDEX idx_im_id ON t_user_device_im(im_id);
+
+CREATE INDEX idx_created_at ON t_user_device_im(created_at);