Hotkeys for record screen

To record a video I need to run the command:
```scrcpy -r file.mkv```
This method is inconvenient if the scrcpy is already running and I need to make a video. I will have to return to the console, close the program, enter the command. After recording the video, I will have to close the scrcpy and reopen it without parameters.

I would like to be able to manage the recording of video from the scrcpy, namely
1. Start recording
2. Pause recording
3. Stop recording

For this, I can use third-party software as OBS, but when I test mobile applications in the scrcpy, switching to between different windows is distracting.

Start by reviewing how the scrcpy -r file.mkv recording command is handled while the application is running. Define the hotkey behavior for starting, pausing, and stopping recording without restarting scrcpy, then verify that each operation works during an active session.

Written by the indexing model from the issue text.