refactor: replace dead_code allow with expect

- Replace #[allow(dead_code)] with #[expect(dead_code)] for better maintainability
- Update EventHandler struct and world_map module to use expect instead of allow

src/event.rs

@@ -15,14 +15,15 @@ pub enum Event {
 }
 
 /// Terminal event handler.
-#[allow(dead_code)]
 #[derive(Debug)]
 pub struct EventHandler {
     /// Event sender channel.
+    #[expect(dead_code)]
     sender: mpsc::UnboundedSender<Event>,
     /// Event receiver channel.
     receiver: mpsc::UnboundedReceiver<Event>,
     /// Event handler thread.
+    #[expect(dead_code)]
     handler: tokio::task::JoinHandle<()>,
 }
 

src/widgets/world_map.rs

@@ -175,7 +175,7 @@ fn area_to_lon_lat(x: u16, y: u16, area: Rect) -> (f64, f64) {
     (lon, lat)
 }
 
-#[allow(dead_code)]
+#[expect(dead_code)]
 /// Convert lon/lat coordinates to area coordinates
 fn lon_lat_to_area(lon: f64, lat: f64, area: Rect) -> (u16, u16) {
     debug_assert!((-180.0..=180.0).contains(&lon));