Introduce AGENTS.md as an entry point for agents, add CODE_MAP.md with a
module overview and diagrams, and create PROGRESS.md to log work
progress.
Update flake.lock to reflect dependency revisions.
- Disable automatic board.advance_turn and replace it with explicit unit
movement handling.
- Add Tunnel structure creation during digging tasks.
- Extend DiggingTask with pop_front and current_target helpers.
- Rename task getters to get_ref_tasks and add mutable get_mut_tasks.
- Update Unit trait and Units enum to expose these new methods.
- Remove unused EMPTY_TASKS lazy static.
- Bump flake.lock revisions, hashes, and timestamps for several
dependencies.
GarandPLG