feat(feishu): add Feishu inbound webhook, /gh commands and card actions

- add feishu_links D1 table and link store helpers
- implement X-Lark-Signature verification, url_verification, /gh login|logout|comment|merge|close and card.action.trigger Merge/Close
- render interactive cards with clickable title link, inline links and callback buttons (no whole-card card_link)
- bind Feishu account in OAuth callback
- document event subscription and required scopes

server/lib/drivers/index.ts

@@ -2,10 +2,12 @@ import type { RouteTarget } from "../types";
 import type { PlatformDriver } from "./types";
 import { DiscordDriver } from "./discord";
 import { TelegramDriver } from "./telegram";
+import { FeishuDriver } from "./feishu";
 
 const drivers: Record<string, PlatformDriver> = {
   discord: new DiscordDriver(),
   telegram: new TelegramDriver(),
+  feishu: new FeishuDriver(),
 };
 
 export function getDriver(target: RouteTarget): PlatformDriver {