Move buildings and units under skirmish_states

Reorganize the codebase by moving the buildings and units modules
into the skirmish_states namespace, updating imports accordingly.

src/app/mod.rs

@@ -1,12 +1,10 @@
 mod app;
-mod buildings;
 pub mod helpers;
 mod keybind;
 mod keybindings;
 mod state;
 pub mod states;
 pub mod threads;
-mod units;
 pub mod view;
 mod views;
 mod widgets;

src/app/states/skirmish.rs

@@ -1,4 +1,4 @@
-use crate::app::{buildings::BaseBuilding, states::skirmish_states::BoardState, units::MinerUnit};
+use crate::app::states::skirmish_states::{BoardState, buildings::BaseBuilding, units::MinerUnit};
 use clap::ValueEnum;
 
 #[derive(Debug, Clone, PartialEq, Eq)]

src/app/states/skirmish_states/board.rs

@@ -1,11 +1,9 @@
 use crate::app::{
-    buildings::BaseBuilding,
     helpers::{CellSizes, cell_size_helper, cells_area_helper},
     states::{
         CellStructure, FocusedCell, Offset, Players, Units, ZoomLevel,
-        skirmish_states::MoveFocusedCell,
+        skirmish_states::{MoveFocusedCell, buildings::BaseBuilding, units::MinerUnit},
     },
-    units::MinerUnit,
     widgets::CellWidget,
 };
 use ratatui::layout::Rect;

src/app/states/skirmish_states/mod.rs

@@ -1,6 +1,8 @@
 mod board;
+pub mod buildings;
 mod focused_cell;
 mod offset;
+pub mod units;
 
 pub use board::BoardState;
 pub use focused_cell::{FocusedCell, MoveFocusedCell};