feat: add group chat and mention-gating to channel adapters

Slack: add requireMention option, resolve bot user ID on connect.
Telegram: add group chat mention/reply-to-bot detection, strip @mention
from message text, default requireMention=true for groups.
WhatsApp: add allowedGroupIds for group chat support, mention detection
via mentionedIds and body text, strip bot mention from messages.

src/channels/telegram/adapter.test.ts

@@ -253,4 +253,187 @@ describe('TelegramAdapter', () => {
 
     expect(next).toHaveBeenCalledTimes(1);
   });
+
+  // ── Group chat mention gating ──────────────────────────────────
+
+  it('ignores group messages without mention when requireMention is true', async () => {
+    const handler = vi.fn();
+    adapter.onMessage(handler);
+
+    await adapter.connect();
+
+    // Simulate onStart callback to set botInfo
+    const startCall = mockStart.mock.calls[0][0];
+    startCall.onStart({ id: 12345, username: 'flynn_bot' });
+
+    const textHandlerCall = mockOn.mock.calls.find(
+      (call) => call[0] === 'message:text',
+    );
+    const textHandler = textHandlerCall![1];
+
+    const ctx = {
+      message: { message_id: 42, text: 'Hello everyone', reply_to_message: undefined },
+      chat: { id: 100, type: 'group' },
+      from: { first_name: 'Will' },
+      replyWithChatAction: vi.fn(),
+    };
+
+    await textHandler(ctx);
+
+    expect(handler).not.toHaveBeenCalled();
+    expect(ctx.replyWithChatAction).not.toHaveBeenCalled();
+  });
+
+  it('processes group messages with bot mention when requireMention is true', async () => {
+    const handler = vi.fn();
+    adapter.onMessage(handler);
+
+    await adapter.connect();
+
+    // Simulate onStart callback to set botInfo
+    const startCall = mockStart.mock.calls[0][0];
+    startCall.onStart({ id: 12345, username: 'flynn_bot' });
+
+    const textHandlerCall = mockOn.mock.calls.find(
+      (call) => call[0] === 'message:text',
+    );
+    const textHandler = textHandlerCall![1];
+
+    const ctx = {
+      message: { message_id: 42, text: '@flynn_bot What is the weather?', reply_to_message: undefined },
+      chat: { id: 100, type: 'group' },
+      from: { first_name: 'Will' },
+      replyWithChatAction: vi.fn(),
+    };
+
+    await textHandler(ctx);
+
+    expect(handler).toHaveBeenCalledTimes(1);
+    const msg: InboundMessage = handler.mock.calls[0][0];
+    expect(msg.text).toBe('What is the weather?');
+  });
+
+  it('processes group messages as reply to bot when requireMention is true', async () => {
+    const handler = vi.fn();
+    adapter.onMessage(handler);
+
+    await adapter.connect();
+
+    // Simulate onStart callback to set botInfo
+    const startCall = mockStart.mock.calls[0][0];
+    startCall.onStart({ id: 12345, username: 'flynn_bot' });
+
+    const textHandlerCall = mockOn.mock.calls.find(
+      (call) => call[0] === 'message:text',
+    );
+    const textHandler = textHandlerCall![1];
+
+    const ctx = {
+      message: {
+        message_id: 42,
+        text: 'Follow up question',
+        reply_to_message: { from: { id: 12345 } },
+      },
+      chat: { id: 100, type: 'supergroup' },
+      from: { first_name: 'Will' },
+      replyWithChatAction: vi.fn(),
+    };
+
+    await textHandler(ctx);
+
+    expect(handler).toHaveBeenCalledTimes(1);
+    const msg: InboundMessage = handler.mock.calls[0][0];
+    expect(msg.text).toBe('Follow up question');
+  });
+
+  it('processes group messages without mention when requireMention is false', async () => {
+    const noMentionAdapter = new TelegramAdapter({
+      ...baseConfig,
+      requireMention: false,
+    });
+    const handler = vi.fn();
+    noMentionAdapter.onMessage(handler);
+
+    await noMentionAdapter.connect();
+
+    // Simulate onStart callback
+    const startCall = mockStart.mock.calls[0][0];
+    startCall.onStart({ id: 12345, username: 'flynn_bot' });
+
+    const textHandlerCall = mockOn.mock.calls.find(
+      (call) => call[0] === 'message:text',
+    );
+    const textHandler = textHandlerCall![1];
+
+    const ctx = {
+      message: { message_id: 42, text: 'Hello everyone', reply_to_message: undefined },
+      chat: { id: 100, type: 'group' },
+      from: { first_name: 'Will' },
+      replyWithChatAction: vi.fn(),
+    };
+
+    await textHandler(ctx);
+
+    expect(handler).toHaveBeenCalledTimes(1);
+    const msg: InboundMessage = handler.mock.calls[0][0];
+    expect(msg.text).toBe('Hello everyone');
+  });
+
+  it('DMs are always processed regardless of requireMention setting', async () => {
+    const handler = vi.fn();
+    adapter.onMessage(handler);
+
+    await adapter.connect();
+
+    // Simulate onStart callback to set botInfo
+    const startCall = mockStart.mock.calls[0][0];
+    startCall.onStart({ id: 12345, username: 'flynn_bot' });
+
+    const textHandlerCall = mockOn.mock.calls.find(
+      (call) => call[0] === 'message:text',
+    );
+    const textHandler = textHandlerCall![1];
+
+    const ctx = {
+      message: { message_id: 42, text: 'Hello Flynn', reply_to_message: undefined },
+      chat: { id: 100, type: 'private' },
+      from: { first_name: 'Will' },
+      replyWithChatAction: vi.fn(),
+    };
+
+    await textHandler(ctx);
+
+    expect(handler).toHaveBeenCalledTimes(1);
+    const msg: InboundMessage = handler.mock.calls[0][0];
+    expect(msg.text).toBe('Hello Flynn');
+  });
+
+  it('strips bot mention from group message text', async () => {
+    const handler = vi.fn();
+    adapter.onMessage(handler);
+
+    await adapter.connect();
+
+    // Simulate onStart callback to set botInfo
+    const startCall = mockStart.mock.calls[0][0];
+    startCall.onStart({ id: 12345, username: 'flynn_bot' });
+
+    const textHandlerCall = mockOn.mock.calls.find(
+      (call) => call[0] === 'message:text',
+    );
+    const textHandler = textHandlerCall![1];
+
+    const ctx = {
+      message: { message_id: 42, text: '@flynn_bot tell me a joke', reply_to_message: undefined },
+      chat: { id: 100, type: 'group' },
+      from: { first_name: 'Will' },
+      replyWithChatAction: vi.fn(),
+    };
+
+    await textHandler(ctx);
+
+    expect(handler).toHaveBeenCalledTimes(1);
+    const msg: InboundMessage = handler.mock.calls[0][0];
+    expect(msg.text).toBe('tell me a joke');
+  });
 });