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/feishu/index.ts

@@ -0,0 +1,37 @@
+import type { RouteTarget, Env, NeutralMessage } from "../../types";
+import type { PlatformDriver, SendResult } from "../types";
+import { getTenantAccessToken, sendMessage, updateMessage } from "./rest";
+import { renderNeutralMessage } from "./render";
+
+export class FeishuDriver implements PlatformDriver {
+  readonly id = "feishu";
+
+  async send(message: NeutralMessage, target: RouteTarget, env: Env): Promise<SendResult> {
+    const chatId = target.chatId ?? "";
+    if (!chatId) {
+      return { ok: false, error: "target.chatId is required", errorCode: "NO_TARGET" };
+    }
+    const tokenRes = await getTenantAccessToken(env);
+    if (!tokenRes.ok || !tokenRes.token) {
+      return { ok: false, error: tokenRes.error ?? "No token", errorCode: tokenRes.errorCode ?? "NO_TOKEN" };
+    }
+    return sendMessage(tokenRes.token, chatId, renderNeutralMessage(message));
+  }
+
+  async edit(
+    message: NeutralMessage,
+    target: RouteTarget,
+    env: Env,
+    messageId: string,
+  ): Promise<SendResult> {
+    const chatId = target.chatId ?? "";
+    if (!chatId) {
+      return { ok: false, error: "target.chatId is required", errorCode: "NO_TARGET" };
+    }
+    const tokenRes = await getTenantAccessToken(env);
+    if (!tokenRes.ok || !tokenRes.token) {
+      return { ok: false, error: tokenRes.error ?? "No token", errorCode: tokenRes.errorCode ?? "NO_TOKEN" };
+    }
+    return updateMessage(tokenRes.token, messageId, renderNeutralMessage(message));
+  }
+}