Consolidate `enabled` and `hours.txt` functionality

[int00h5525]

Summary

Instead of having both an enabled and hours.txt file to manage server state, use a single file

Motivation

Simplify documentation and expected behavior

Describe alternatives you've considered

A fancy table

Behavior	hours.txt enabled	hours.txt disabled	hours.txt doesn't exist/unparsable
enabled exists	enabled	disabled	enabled
enabled doesn't exist	disabled	disabled	disabled

Additional context