feat: 텔레그램 미니앱 연동

- sendMessageWithKeyboard 함수 추가
- /start 명령어에 미니앱 버튼 추가
- 메뉴 버튼으로 서비스 페이지 열기 지원

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/index.ts

@@ -1,6 +1,6 @@
 import { Env, TelegramUpdate } from './types';
 import { validateWebhookRequest, checkRateLimit } from './security';
-import { sendMessage, setWebhook, getWebhookInfo, sendChatAction } from './telegram';
+import { sendMessage, sendMessageWithKeyboard, setWebhook, getWebhookInfo, sendChatAction } from './telegram';
 import {
   addToBuffer,
   processAndSummarize,
@@ -76,6 +76,15 @@ async function handleMessage(
     const [command, ...argParts] = text.split(' ');
     const args = argParts.join(' ');
     responseText = await handleCommand(env, userId, chatIdStr, command, args);
+
+    // /start 명령어는 미니앱 버튼과 함께 전송
+    if (command === '/start') {
+      await sendMessageWithKeyboard(env.BOT_TOKEN, chatId, responseText, [
+        [{ text: '🌐 서비스 보기', web_app: { url: 'https://anvil-hosting.pages.dev' } }],
+        [{ text: '💬 문의하기', url: 'https://t.me/AnvilForgeBot' }],
+      ]);
+      return;
+    }
   } else {
     // 타이핑 표시
     await sendChatAction(env.BOT_TOKEN, chatId, 'typing');

src/telegram.ts

@@ -82,6 +82,54 @@ export async function deleteWebhook(
   return response.json();
 }
 
+// 인라인 키보드 타입
+export interface InlineKeyboardButton {
+  text: string;
+  url?: string;
+  callback_data?: string;
+  web_app?: { url: string };
+}
+
+// 인라인 키보드와 함께 메시지 전송
+export async function sendMessageWithKeyboard(
+  token: string,
+  chatId: number,
+  text: string,
+  keyboard: InlineKeyboardButton[][],
+  options?: {
+    parse_mode?: 'HTML' | 'Markdown' | 'MarkdownV2';
+  }
+): Promise<boolean> {
+  try {
+    const response = await fetch(
+      `https://api.telegram.org/bot${token}/sendMessage`,
+      {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({
+          chat_id: chatId,
+          text,
+          parse_mode: options?.parse_mode || 'HTML',
+          reply_markup: {
+            inline_keyboard: keyboard,
+          },
+        }),
+      }
+    );
+
+    if (!response.ok) {
+      const error = await response.text();
+      console.error('Telegram API error:', error);
+      return false;
+    }
+
+    return true;
+  } catch (error) {
+    console.error('Failed to send message with keyboard:', error);
+    return false;
+  }
+}
+
 // 타이핑 액션 전송
 export async function sendChatAction(
   token: string,