[Time] Create a `TimePlugin`

The time plugin emits events whenever time-related things happen, such as a new day started.

Can be used for a daily reset

Look for existing plugin implementations in the codebase to understand the plugin interface. The issue mentions emitting events for time-related occurrences like a new day; find where time is managed in the engine. Determine how to register the plugin and hook it into the game loop. A test should verify events are emitted correctly.

Written by the indexing model from the issue text.