Privatize internal modules and adjust re‑exports

src/app/states/skirmish_states/mod.rs

@@ -1,6 +1,6 @@
-pub mod board;
-pub mod focused_cell;
-pub mod offset;
+mod board;
+mod focused_cell;
+mod offset;
 
 pub use board::BoardState;
 pub use focused_cell::{FocusedCell, MoveFocusedCell};