fix: 修正 logo 中 N 和 G 字母造型

N 添加对角线笔画（█▄ █），G 添加内横杠（█ ▀█），
避免与 O 字母造型雷同。同步更新 ui.ts 中的硬编码 wordmark。

packages/core/migration/20260427172553_slow_nightmare/migration.sql

@@ -0,0 +1,17 @@
+CREATE TABLE `session_message` (
+	`id` text PRIMARY KEY,
+	`session_id` text NOT NULL,
+	`type` text NOT NULL,
+	`time_created` integer NOT NULL,
+	`time_updated` integer NOT NULL,
+	`data` text NOT NULL,
+	CONSTRAINT `fk_session_message_session_id_session_id_fk` FOREIGN KEY (`session_id`) REFERENCES `session`(`id`) ON DELETE CASCADE
+);
+--> statement-breakpoint
+DROP INDEX IF EXISTS `session_entry_session_idx`;--> statement-breakpoint
+DROP INDEX IF EXISTS `session_entry_session_type_idx`;--> statement-breakpoint
+DROP INDEX IF EXISTS `session_entry_time_created_idx`;--> statement-breakpoint
+CREATE INDEX `session_message_session_idx` ON `session_message` (`session_id`);--> statement-breakpoint
+CREATE INDEX `session_message_session_type_idx` ON `session_message` (`session_id`,`type`);--> statement-breakpoint
+CREATE INDEX `session_message_time_created_idx` ON `session_message` (`time_created`);--> statement-breakpoint
+DROP TABLE `session_entry`;