feat: add Zig color scheme support

- Add Zig colors to dark, light, and ascii themes
- Add lang_zig field to ColorScheme struct
- Implement Colors::lang_zig() method

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: unhappychoice

assets/languages/lang_ascii.json

@@ -15,5 +15,6 @@
   "lang_scala": "red",
   "lang_haskell": "magenta",
   "lang_dart": "cyan",
+  "lang_zig": "yellow",
   "lang_default": "white"
 }

assets/languages/lang_dark.json

@@ -15,5 +15,6 @@
   "lang_scala": {"r": 220, "g": 50, "b": 47},
   "lang_haskell": {"r": 94, "g": 80, "b": 134},
   "lang_dart": {"r": 0, "g": 180, "b": 240},
+  "lang_zig": {"r": 249, "g": 169, "b": 60},
   "lang_default": {"r": 255, "g": 255, "b": 255}
 }

assets/languages/lang_light.json

@@ -15,5 +15,6 @@
   "lang_scala": {"r": 220, "g": 50, "b": 47},
   "lang_haskell": {"r": 94, "g": 80, "b": 134},
   "lang_dart": {"r": 0, "g": 120, "b": 180},
+  "lang_zig": {"r": 189, "g": 99, "b": 0},
   "lang_default": {"r": 64, "g": 64, "b": 64}
 }

src/domain/models/color_scheme.rs

@@ -146,6 +146,7 @@ pub struct ColorScheme {
     pub lang_scala: SerializableColor,
     pub lang_haskell: SerializableColor,
     pub lang_dart: SerializableColor,
+    pub lang_zig: SerializableColor,
     pub lang_default: SerializableColor,
 }
 
@@ -320,6 +321,10 @@ impl ColorScheme {
                 .get("lang_dart")
                 .cloned()
                 .unwrap_or(SerializableColor::Name("blue".to_string())),
+            lang_zig: lang_colors
+                .get("lang_zig")
+                .cloned()
+                .unwrap_or(SerializableColor::Name("yellow".to_string())),
             lang_default: lang_colors
                 .get("lang_default")
                 .cloned()

src/presentation/ui/colors.rs

@@ -153,6 +153,9 @@ impl Colors {
     pub fn lang_dart() -> Color {
         Self::get_color_scheme().lang_dart.into()
     }
+    pub fn lang_zig() -> Color {
+        Self::get_color_scheme().lang_zig.into()
+    }
     pub fn lang_default() -> Color {
         Self::get_color_scheme().lang_default.into()
     }