Add Stone and Tunnel, refactor CellStructure

Introduce new building types Stone and Tunnel with their own tag, color,
and
properties. CellStructure now holds these structs (Tunnel, Stone)
instead of
simple variants. BaseBuilding is simplified to return a char tag and a
color
based on owner. BoardState creation and CellWidget rendering are updated
to
use the new building structs and their methods.

src/app/widgets/cell.rs

@@ -1,4 +1,4 @@
-use crate::app::states::{CellStructure, Players, Units, ZoomLevel};
+use crate::app::states::{CellStructure, Units, ZoomLevel, skirmish_states::buildings::Stone};
 use ratatui::{
     buffer::Buffer,
     layout::{Alignment, Rect},
@@ -75,7 +75,7 @@ impl CellWidget {
     }
 
     fn display_coords(&self) -> Span<'_> {
-        if self.selected || self.structure != CellStructure::Stone || self.marked {
+        if self.selected || self.structure != CellStructure::Stone(Stone::new()) || self.marked {
             format!("{}{}", self.col_to_letters(), self.row).green()
         } else {
             "".to_span()
@@ -83,38 +83,43 @@ impl CellWidget {
     }
 
     fn fg_color(&self) -> Color {
-        match self.structure {
-            _ if self.marked && self.selected => Color::Magenta,
-            _ if self.marked && !self.selected => Color::LightMagenta,
-            _ if self.selected && !self.marked => Color::LightYellow,
-            CellStructure::Base(base) if !self.selected => match base.get_owner() {
-                Players::Player => Color::LightBlue,
-                Players::Enemy => Color::LightRed,
-            },
-            CellStructure::Tunel if !self.selected => Color::Gray,
-            _ => Color::White,
+        if self.marked && self.selected {
+            return Color::Magenta;
+        } else if self.marked && !self.selected {
+            return Color::LightMagenta;
+        } else if self.selected && !self.marked {
+            return Color::LightYellow;
         }
+
+        if !self.selected {
+            return match self.structure {
+                CellStructure::Base(base) => base.get_color(),
+                CellStructure::Tunnel(tunnel) => tunnel.get_color(),
+                CellStructure::Stone(stone) => stone.get_color(),
+            };
+        }
+
+        Color::White
     }
 
     fn get_text_area(&self) -> Vec<Line<'_>> {
-        let tag: &str = match self.structure {
+        let tag: char = match self.structure {
             CellStructure::Base(base) => base.get_tag(),
-            CellStructure::Tunel => "T",
-            CellStructure::Stone => " ",
-            // _ => " ",
+            CellStructure::Tunnel(tunnel) => tunnel.get_tag(),
+            CellStructure::Stone(stone) => stone.get_tag(),
         };
 
-        let b_level: &str = match self.structure {
+        let b_level: char = match self.structure {
             CellStructure::Base(base) => base.get_level(),
-            _ => " ",
+            _ => ' ',
         };
 
-        let unit: &str = match self.unit {
+        let unit: char = match self.unit {
             Some(unit) => match unit {
                 Units::Miner(miner) => miner.get_tag(),
-                // _ => " ",
+                // _ => ' ',
             },
-            None => " ",
+            None => ' ',
         };
 
         let mut text_area: Vec<Line<'_>> = Vec::new();