fix: update sendMessage test expectations for Markdown parse_mode

The sendTelegramMessage helper now passes { parse_mode: 'Markdown' }
to bot.api.sendMessage, but three tests still expected only two args.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/channels/telegram.test.ts

@@ -710,6 +710,7 @@ describe('TelegramChannel', () => {
       expect(currentBot().api.sendMessage).toHaveBeenCalledWith(
         '100200300',
         'Hello',
+        { parse_mode: 'Markdown' },
       );
     });
 
@@ -723,6 +724,7 @@ describe('TelegramChannel', () => {
       expect(currentBot().api.sendMessage).toHaveBeenCalledWith(
         '-1001234567890',
         'Group message',
+        { parse_mode: 'Markdown' },
       );
     });
 
@@ -739,11 +741,13 @@ describe('TelegramChannel', () => {
         1,
         '100200300',
         'x'.repeat(4096),
+        { parse_mode: 'Markdown' },
       );
       expect(currentBot().api.sendMessage).toHaveBeenNthCalledWith(
         2,
         '100200300',
         'x'.repeat(904),
+        { parse_mode: 'Markdown' },
       );
     });