```
feat: Refactor calendar feature into blueprint
- Moved calendar logic from `features/calendar.py` and `app.py` into a new blueprint at `routes/calendar.py`.
- Removed the `Calendar` class and refactored logic into helper functions within the blueprint module for better organization and readability.
- Eliminated the `pandas` dependency for date range generation, using standard `datetime` operations instead.
- Resolved circular import issues between `db.py`, `extensions.py`, and `routes/calendar.py` by adjusting import locations.
- Corrected `url_for` calls in templates (`calendar.html`, `partials/people_link.html`) to reference the new blueprint endpoint (`calendar.get_calendar`).
- Fixed an `AttributeError` related to HTMX request checking in the calendar route.
- Corrected `AttributeError` related to `.date()` calls on `datetime.date` objects in view processing functions.
- Updated `templates/changelog/changelog.html` to document the refactoring and associated fixes.
```
