Enhance Rota Management System

- Updated .gitignore to exclude 'cons/' directory.
- Refactored gen_cons.py to extract leave and rota assignments from calendar data, and added functionality to handle shift assignments from rota data.
- Modified timetable.css to include styles for force-assigned shifts.
- Enhanced shifts.py to manage forced assignments and handle leave conflicts, including new methods for date-based assignments.
- Updated workers.py to introduce structured hard day dependencies and exclusions, allowing for more flexible scheduling.
- Adjusted test_workers.py to reflect changes in hard day dependency and exclusion methods, ensuring compatibility with new data structures.

.gitignore

@@ -13,3 +13,5 @@ logs/
 
 *.db
 web/rota
+
+cons/