feat: server skeleton with authenticate and complete_mfa tools

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

tests/test_server.py

@@ -0,0 +1,66 @@
+import json
+import queue
+import threading
+from unittest.mock import MagicMock, patch
+
+import pytest
+
+import server
+
+
+@pytest.fixture(autouse=True)
+def reset_state():
+    original_state = server._auth_state
+    original_client = server._client
+    for q in (server._mfa_input_queue, server._login_result_queue):
+        while not q.empty():
+            try:
+                q.get_nowait()
+            except queue.Empty:
+                break
+    yield
+    server._auth_state = original_state
+    server._client = original_client
+
+
+def test_check_auth_unauthenticated():
+    server._auth_state = "unauthenticated"
+    assert server._check_auth() == "Not authenticated. Ask Claude to call authenticate() first."
+
+
+def test_check_auth_authenticated():
+    server._auth_state = "authenticated"
+    assert server._check_auth() is None
+
+
+def test_authenticate_success():
+    with patch("server.Garmin") as mock_garmin_cls:
+        mock_garmin_cls.return_value = MagicMock()
+        # mock login() returns immediately, thread puts success in queue
+        result = server.authenticate()
+        assert result == "Authenticated successfully."
+        assert server._auth_state == "authenticated"
+
+
+def test_authenticate_mfa_required():
+    with patch("server.Garmin") as mock_garmin_cls:
+        mock_garmin_cls.return_value = MagicMock()
+        with patch.object(server._login_result_queue, "get", side_effect=queue.Empty):
+            result = server.authenticate()
+        assert "MFA required" in result
+        assert server._auth_state == "mfa_pending"
+
+
+def test_complete_mfa_success():
+    server._auth_state = "mfa_pending"
+    server._login_result_queue.put(("success", None))
+    result = server.complete_mfa("123456")
+    assert result == "MFA accepted. Authenticated successfully."
+    assert server._auth_state == "authenticated"
+    assert server._mfa_input_queue.get_nowait() == "123456"
+
+
+def test_complete_mfa_not_in_progress():
+    server._auth_state = "unauthenticated"
+    result = server.complete_mfa("123456")
+    assert result == "No MFA in progress. Call authenticate() first."