- Added `remove_done` function to clean up finished appointments in the database.
- Introduced `get_upcoming_for_user` function to retrieve upcoming appointments for a specific user.
- Updated `backend_server.py` to include a new endpoint for fetching user-specific upcoming events.
- Modified `blueprint.py` to render upcoming events in the user interface.
- Enhanced `terminplan.html` to display a list of upcoming appointments with relevant details and action links.
- Updated configuration to enable the new appointment planning feature.
- Implemented `excel_export.py` for generating library item exports in Excel format.
- Created `pdf_export.py` for generating audit reports compliant with DIN 5008 standards, including detailed event tables and signature blocks.
- Developed `generate_user.py` for interactive user creation with validation for usernames and passwords.
- Introduced `module_registry.py` for managing module states and path matching.
- Added a basic `__init__.py` in the `terminplaner` module for initialization.