Executing a long-running process via `hotkeys` causes all subsequent presses to wait until the process has exited before it can run them. [This loop](https://github.com/arcnmx/screenstub/blob/af5a08b3349de6fb07a8c20898a6c3cf89450100/qemu/src/lib.rs#L166) is the culprit, since it holds on to the exclusive `qga` socket lock until it finally has a return value.
