fix(calendar): address PR feedback from maintainer

- Remove CHANGELOG.md changes (auto-generated from commits)
- Move all parameter descriptions into function docstrings for LLM context
- Remove unused caldav dependency (using httpx for CalDAV implementation)
- Move datetime imports to top of modules
- Remove load_dotenv from tests/conftest.py
- Clarify Event vs Meeting distinction in docstrings
- Handle 401 auth errors gracefully in calendar tests

Addresses all feedback from PR #95 review

pyproject.toml

@@ -11,7 +11,6 @@ dependencies = [
     "mcp[cli] (>=1.10,<1.11)",
     "httpx (>=0.28.1,<0.29.0)",
     "pillow (>=11.2.1,<12.0.0)",
-    "caldav (>=1.3.6,<2.0.0)",
     "icalendar (>=6.0.0,<7.0.0)"
 ]