feat: Telegram Bot API integration

- New client: src/clients/telegram.ts
- Tools: telegram_get_me, telegram_send_message, telegram_send_photo, telegram_get_updates, telegram_get_chat
- REST endpoints: GET /api/telegram/me, POST /api/telegram/message, POST /api/telegram/photo, GET /api/telegram/updates, GET /api/telegram/chat
- Multi-account env var pattern: TELEGRAM_{ACCOUNT}_BOT_TOKEN
- Uses Telegram Bot API (https://api.telegram.org)

Total tools: 24 (email 6, obsidian 5, whatsapp 3, linkedin 4, telegram 5)

src/clients/telegram.ts

@@ -0,0 +1,129 @@
+const TELEGRAM_API_BASE = 'https://api.telegram.org';
+
+function getToken(account: string): string {
+  const envKey = `TELEGRAM_${account.toUpperCase()}_BOT_TOKEN`;
+  return process.env[envKey] ?? '';
+}
+
+async function telegramRequest(
+  token: string,
+  method: string,
+  params?: Record<string, unknown>
+) {
+  const url = `${TELEGRAM_API_BASE}/bot${token}/${method}`;
+  const res = await fetch(url, {
+    method: params ? 'POST' : 'GET',
+    headers: params ? { 'Content-Type': 'application/json' } : undefined,
+    body: params ? JSON.stringify(params) : undefined,
+    signal: AbortSignal.timeout(15000),
+  });
+
+  const data = await res.json();
+  if (!data.ok) {
+    throw new Error(`Telegram API error: ${data.description ?? 'Unknown error'}`);
+  }
+  return data.result;
+}
+
+export async function getMe(args: { account?: string }): Promise<{
+  id: number;
+  first_name: string;
+  username: string;
+  is_bot: boolean;
+}> {
+  const token = getToken(args.account ?? 'default');
+  if (!token) {
+    throw new Error('Missing Telegram credentials. Set TELEGRAM_{ACCOUNT}_BOT_TOKEN');
+  }
+  return telegramRequest(token, 'getMe');
+}
+
+export async function sendMessage(args: {
+  chat_id: string | number;
+  text: string;
+  parse_mode?: 'HTML' | 'Markdown' | 'MarkdownV2';
+  account?: string;
+}): Promise<{ message_id: number; chat_id: string | number }> {
+  const token = getToken(args.account ?? 'default');
+  if (!token) {
+    throw new Error('Missing Telegram credentials. Set TELEGRAM_{ACCOUNT}_BOT_TOKEN');
+  }
+
+  const result = await telegramRequest(token, 'sendMessage', {
+    chat_id: args.chat_id,
+    text: args.text,
+    parse_mode: args.parse_mode,
+  });
+
+  return {
+    message_id: result.message_id,
+    chat_id: result.chat.id,
+  };
+}
+
+export async function sendPhoto(args: {
+  chat_id: string | number;
+  photo: string;
+  caption?: string;
+  account?: string;
+}): Promise<{ message_id: number; chat_id: string | number }> {
+  const token = getToken(args.account ?? 'default');
+  if (!token) {
+    throw new Error('Missing Telegram credentials. Set TELEGRAM_{ACCOUNT}_BOT_TOKEN');
+  }
+
+  const result = await telegramRequest(token, 'sendPhoto', {
+    chat_id: args.chat_id,
+    photo: args.photo,
+    caption: args.caption,
+  });
+
+  return {
+    message_id: result.message_id,
+    chat_id: result.chat.id,
+  };
+}
+
+export async function getUpdates(args: {
+  limit?: number;
+  account?: string;
+}): Promise<Array<{
+  update_id: number;
+  message?: {
+    message_id: number;
+    from?: { id: number; first_name: string; username?: string };
+    chat: { id: number; type: string; title?: string };
+    date: number;
+    text?: string;
+  };
+}>> {
+  const token = getToken(args.account ?? 'default');
+  if (!token) {
+    throw new Error('Missing Telegram credentials. Set TELEGRAM_{ACCOUNT}_BOT_TOKEN');
+  }
+
+  return telegramRequest(token, 'getUpdates', {
+    limit: args.limit ?? 10,
+  });
+}
+
+export async function getChat(args: {
+  chat_id: string | number;
+  account?: string;
+}): Promise<{
+  id: number;
+  type: string;
+  title?: string;
+  username?: string;
+  description?: string;
+  member_count?: number;
+}> {
+  const token = getToken(args.account ?? 'default');
+  if (!token) {
+    throw new Error('Missing Telegram credentials. Set TELEGRAM_{ACCOUNT}_BOT_TOKEN');
+  }
+
+  return telegramRequest(token, 'getChat', {
+    chat_id: args.chat_id,
+  });
+}