Keep the program running while monitor is turned off

- [x ] I have checked that a similar [feature request](https://github.com/Genymobile/scrcpy/issues?q=is%3Aopen+is%3Aissue+label%3A%22feature+request%22) does not already exist.

**Is your feature request related to a problem? Please describe.**
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the screen doesn't change if I turn off monitor.

**Describe the solution you'd like**
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the program should continue to run and not have the screen freeze

**Describe alternatives you've considered**
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none

**Additional context**
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The issue names no files, tests, or entry points. Reproduce the freeze by turning off the host monitor while scrcpy is running, then trace the display and Android screen-handling paths to identify where progress stops. Done means the program continues running and the mirrored screen does not freeze in this situation.

Written by the indexing model from the issue text.