Remove debug logging for DF11 messages

- Cleaned up temporary debug output that was added for testing
- DF11 message processing is working correctly, no longer needs logging

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

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

internal/modes/decoder.go

@@ -233,10 +233,6 @@ func (d *Decoder) Decode(data []byte) (*Aircraft, error) {
 	df := (data[0] >> 3) & 0x1F
 	icao := d.extractICAO(data, df)
 	
-	// Debug: Log DF types to verify we're processing new formats
-	if df == 0 || df == 11 || df == 16 || df == 19 || df == 24 {
-		fmt.Printf("DEBUG: Processing new DF%d message for ICAO %06X\n", df, icao)
-	}
 
 	aircraft := &Aircraft{
 		ICAO24: icao,