feat(channels): add hook channel

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

nanobot/channels/hook.py

@@ -0,0 +1,38 @@
+"""Hook channel — receives outbound messages from hook-initiated conversations."""
+
+from loguru import logger
+
+from nanobot.bus.events import OutboundMessage
+from nanobot.bus.queue import MessageBus
+
+
+class HookChannel:
+    """
+    Minimal channel for hook-initiated conversations.
+
+    The hook HTTP server publishes InboundMessages to the bus.
+    Responses come back as OutboundMessages routed here.
+    send() is a no-op because the HTTP caller gets the response
+    via bus correlation, not channel delivery.
+    """
+
+    name = "hook"
+
+    def __init__(self, bus: MessageBus):
+        self.bus = bus
+        self._running = False
+
+    async def start(self) -> None:
+        self._running = True
+        logger.info("Hook channel started")
+
+    async def stop(self) -> None:
+        self._running = False
+
+    async def send(self, msg: OutboundMessage) -> None:
+        """No-op — response is returned via bus correlation to the HTTP caller."""
+        logger.debug(f"Hook channel received outbound for {msg.chat_id} (no-op)")
+
+    @property
+    def is_running(self) -> bool:
+        return self._running

tests/test_hook_channel.py

@@ -0,0 +1,37 @@
+"""Tests for the hook channel."""
+
+import pytest
+from unittest.mock import MagicMock
+from nanobot.channels.hook import HookChannel
+from nanobot.bus.queue import MessageBus
+from nanobot.bus.events import OutboundMessage
+
+
+@pytest.fixture
+def bus():
+    return MessageBus()
+
+
+def test_hook_channel_name():
+    bus = MessageBus()
+    channel = HookChannel(bus)
+    assert channel.name == "hook"
+
+
+@pytest.mark.asyncio
+async def test_hook_channel_send_is_noop():
+    """send() should not raise and should not do anything."""
+    bus = MessageBus()
+    channel = HookChannel(bus)
+    msg = OutboundMessage(channel="hook", chat_id="test", content="hello")
+    await channel.send(msg)  # Should not raise
+
+
+@pytest.mark.asyncio
+async def test_hook_channel_start_stop():
+    bus = MessageBus()
+    channel = HookChannel(bus)
+    await channel.start()
+    assert channel.is_running
+    await channel.stop()
+    assert not channel.is_running