refactor: move terminal guard to own file

src/terminal_guard.rs

@@ -0,0 +1,29 @@
+use crossterm::cursor::Show;
+use crossterm::execute;
+use crossterm::terminal::{LeaveAlternateScreen, disable_raw_mode};
+
+pub struct TerminalModeGuard {
+    active: bool,
+}
+
+impl TerminalModeGuard {
+    pub fn new() -> Self {
+        Self { active: true }
+    }
+
+    pub fn cleanup(&mut self) {
+        if !self.active {
+            return;
+        }
+        let _ = disable_raw_mode();
+        let mut stdout = std::io::stdout();
+        let _ = execute!(stdout, LeaveAlternateScreen, Show);
+        self.active = false;
+    }
+}
+
+impl Drop for TerminalModeGuard {
+    fn drop(&mut self) {
+        self.cleanup();
+    }
+}