feat(bot): add MAX notifications adapter and operator handoff

Refs #83

tests/test_max_setup.py

@@ -0,0 +1,51 @@
+"""Operator tools do not send messages or expose credentials."""
+
+from unittest.mock import AsyncMock
+
+import pytest
+
+from app.channels import max_setup
+from app.channels.max_client import MaxApiError
+from app.config import Settings
+
+
+@pytest.fixture
+def client(monkeypatch):
+    settings = Settings(_env_file=None, max_bot_username="test_bot", max_webhook_url="https://api.example.org/hook")
+    sender = AsyncMock()
+    sender.request.return_value = {"is_bot": True, "username": "test_bot"}
+    monkeypatch.setattr(max_setup, "Settings", lambda **kwargs: settings)
+    monkeypatch.setattr(max_setup, "MaxClient", lambda cfg: sender)
+    return sender
+
+
+async def test_check_only_reads_bot_identity(client):
+    await max_setup.run("check")
+    client.request.assert_awaited_once_with("GET", "/me")
+    client.subscribe.assert_not_called()
+    client.send.assert_not_called()
+    client.close.assert_awaited_once()
+
+
+async def test_subscribe_is_explicit_and_checks_bot_first(client):
+    await max_setup.run("subscribe")
+    client.subscribe.assert_awaited_once()
+    client.send.assert_not_called()
+
+
+async def test_mismatched_bot_does_not_change_webhooks(client):
+    client.request.return_value = {"is_bot": True, "username": "another_bot"}
+    with pytest.raises(MaxApiError, match="bot_username_mismatch"):
+        await max_setup.run("subscribe")
+    client.subscribe.assert_not_called()
+    client.close.assert_awaited_once()
+
+
+async def test_status_checks_exact_configured_webhook(client):
+    client.request.side_effect = [
+        {"is_bot": True, "username": "test_bot"},
+        {"subscriptions": [{"url": "https://elsewhere.example.org"}]},
+    ]
+    with pytest.raises(MaxApiError, match="webhook_missing"):
+        await max_setup.run("status")
+    client.subscribe.assert_not_called()