feat: 机器人管理 — 删除、编辑配置、完整创建表单

- PUT /api/bot/:id 更新机器人配置（保存到数据库，重启生效）
- GET /api/bot/:id/config 获取保存的配置
- BotManager.updateBot/getBotConfig 方法
- Settings 页面：删除按钮（带确认）、编辑弹窗（修改所有字段）
- 创建表单：完整字段（名称、地址、端口、昵称、默认频道）

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/bot/manager.ts

@@ -93,6 +93,27 @@ export class BotManager {
     this.logger.info({ botId: id }, "Bot instance removed");
   }
 
+  updateBot(id: string, params: Partial<CreateBotParams>): void {
+    const instances = this.database.getBotInstances();
+    const existing = instances.find((i) => i.id === id);
+    if (!existing) throw new Error(`Bot ${id} not found`);
+
+    this.database.saveBotInstance({
+      ...existing,
+      name: params.name ?? existing.name,
+      serverAddress: params.serverAddress ?? existing.serverAddress,
+      serverPort: params.serverPort ?? existing.serverPort,
+      nickname: params.nickname ?? existing.nickname,
+      defaultChannel: params.defaultChannel ?? existing.defaultChannel,
+      channelPassword: params.channelPassword ?? existing.channelPassword,
+    });
+    this.logger.info({ botId: id }, "Bot instance config updated (restart to apply)");
+  }
+
+  getBotConfig(id: string): import("../data/database.js").BotInstance | undefined {
+    return this.database.getBotInstances().find((i) => i.id === id);
+  }
+
   getBot(id: string): BotInstance | undefined {
     return this.bots.get(id);
   }