Handle systemd OSC 3008 spec, otherwise gibberish in the terminal

systemd version 258 introduces OSC 3008 spec recently.

[https://github.com/systemd/systemd/blob/main/docs/OSC_CONTEXT.md](https://github.com/systemd/systemd/blob/main/docs/OSC_CONTEXT.md)

[https://systemd.io/OSC_CONTEXT/](https://systemd.io/OSC_CONTEXT/)

These escape codes are handled nicely by most terminals and, IMHO, should be kept that way.
Unfortunately, WindTerm fails to handle OSC escape codes in general, leading to gibberish littered all over the prompt.

#### Quick workaround:
If you are using systemd 258 and observed littering behavior:
**Method 1.** Remove the file /etc/profile.d/80-systemd-osc-context.sh
**Method 2.** `unset` the variable `PS0` and `PROMPT_COMMAND`

#### Long-term fix required:
Handle these OSC escape codes in WindTerm.

Reproduce the issue with systemd 258 and the OSC 3008 sequences emitted by /etc/profile.d/80-systemd-osc-context.sh, including the PS0 and PROMPT_COMMAND workaround. Trace how WindTerm processes terminal escape codes; done means OSC 3008 is handled without gibberish while normal prompt output remains intact.

Written by the indexing model from the issue text.