Fix Ctrl+C handling in OSC playback

src/osc_sender.py

@@ -84,8 +84,6 @@ class OSCSender:
             print("No chords loaded!")
             return
 
-        try:
-            import threading
         import tty
         import termios
         import os
@@ -95,20 +93,27 @@ class OSCSender:
         self.display_chord(self.current_index)
 
         def get_key():
-                """Get a single keypress."""
+            """Get a single keypress. Returns None on error."""
+            try:
                 fd = sys.stdin.fileno()
                 old_settings = termios.tcgetattr(fd)
                 try:
                     tty.setraw(sys.stdin.fileno())
                     ch = sys.stdin.read(1)
+                    return ch
                 finally:
                     termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
-                return ch
+            except (termios.error, OSError):
+                # Fallback for non-tty environments
+                return sys.stdin.read(1) if sys.stdin else None
 
         print("\nUse arrow keys to navigate. Press Ctrl+C to quit.")
 
+        try:
             while True:
                 key = get_key()
+                if key is None:
+                    break
 
                 # Left arrow
                 if key == "\x1b":  # Escape sequence start
@@ -140,6 +145,8 @@ class OSCSender:
 
         except KeyboardInterrupt:
             print("\n\nPlayback stopped.")
+        except Exception:
+            pass  # Clean exit for any other error
 
     def send_all(self):
         """Send all chords in sequence (for testing)."""