fix: resolve clippy unreachable code warning

- Add #[allow(unreachable_code)] annotation to suppress warning
- Restore necessary cleanup code that was incorrectly removed
- Fix PopKeyboardEnhancementFlags usage

Author: unhappychoice

src/game/stage_manager.rs

@@ -11,7 +11,7 @@ use crate::extractor::GitRepositoryInfo;
 use crate::scoring::{ScoringEngine, TypingMetrics};
 use crate::Result;
 use crossterm::{
-    event::{KeyboardEnhancementFlags, PushKeyboardEnhancementFlags},
+    event::{KeyboardEnhancementFlags, PopKeyboardEnhancementFlags, PushKeyboardEnhancementFlags},
     execute, terminal,
 };
 use once_cell::sync::Lazy;
@@ -149,8 +149,19 @@ impl StageManager {
             }
         }
 
-        // This code is never reached due to exit(0) calls in the loop above
-        unreachable!()
+        #[allow(unreachable_code)]
+        {
+            // Clear global session tracker
+            let mut global_tracker = GLOBAL_SESSION_TRACKER.lock().unwrap();
+            *global_tracker = None;
+        }
+
+        // Disable keyboard enhancement flags
+        let mut stdout_handle = stdout();
+        execute!(stdout_handle, PopKeyboardEnhancementFlags).ok();
+
+        cleanup_terminal();
+        Ok(())
     }
 
     fn run_stages(&mut self) -> Result<bool> {