examples : Make microphone example draw the waveform with linear inte…

Without linear interpolation : <img width="274" height="453" alt="image" src="https://github.com/user-attachments/assets/dc70e85f-1350-4c37-803c-4a8787fd8c6d" /> With linear interpolation : <img width="272" height="448" alt="image" src="https://github.com/user-attachments/assets/38f54e3c-df8b-4b21-9287-0b9f0ebc8bbf" /> The pr also make the X button stop recording until pressed again.