fix: address PR #632 review comments

- Update stale httpx reference to niquests in calendar.py type comment
- Replace inline inspect.isawaitable with _maybe_await helper in tests
- Fix incorrect port number in docker-compose unstructured comment
- Remove commented-out smithery service block (dead code)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

tests/client/calendar/test_field_preservation.py

@@ -4,13 +4,14 @@ This test module demonstrates data loss issues when non-supported fields
 are present in calendar events and contacts during round-trip operations.
 """
 
-import inspect
 import logging
 import uuid
 from datetime import datetime, timedelta
 
 import pytest
 
+from nextcloud_mcp_server.client.calendar import _maybe_await
+
 logger = logging.getLogger(__name__)
 
 
@@ -36,9 +37,7 @@ async def test_calendar_event_custom_fields_preservation(nc_client):
         # Get the calendar object from the caldav library
         calendar = nc_client.calendar._get_calendar(calendar_name)
         event = await nc_client.calendar._async_object_by_uid(calendar, event_uid)
-        result = event.load()
-        if inspect.isawaitable(result):
-            await result
+        await _maybe_await(event.load())
 
         # Now manually inject custom iCal properties into the raw data
         # This simulates what would happen if the event was created by another CalDAV client
@@ -310,9 +309,7 @@ async def test_calendar_event_roundtrip_data_loss_demonstration(nc_client):
         # Get the calendar object and event
         calendar = nc_client.calendar._get_calendar(calendar_name)
         event = await nc_client.calendar._async_object_by_uid(calendar, event_uid)
-        result = event.load()
-        if inspect.isawaitable(result):
-            await result
+        await _maybe_await(event.load())
 
         # Inject additional iCal properties that are valid but not supported by our parser
         extended_ical = f"""BEGIN:VCALENDAR