Add wayland-spectre

[WanderingM0nster]

Adds wayland-spectre, a Wayland screen-share diagnostic GUI for KDE Plasma. Detects seven known portal/compositor failure modes and reports actionable fixes.

• Project: https://github.com/WanderingM0nster/wayland-spectre
• License: GPL-3.0

Resubmitted in the correct single-line-URL format per the README. Apologies for #3733.

[probonopd]

Does it work on X11? We only list applications here that (also) work on X11. Thanks!

[WanderingM0nster]

Yes, it works on X11. Your question also exposed a real presentation problem, so thank you for it: the app launched fine on X11 but reported every Wayland-specific check as FAIL, which made it look broken rather than not applicable. I have released v0.4.1 to fix exactly that.

As of v0.4.1:

• the app detects the session type at startup (XDG_SESSION_TYPE, with WAYLAND_DISPLAY/DISPLAY as fallback)
• on X11 the Wayland-specific checks report SKIP, with a banner explaining that those layers are not in use on X11; the portal, PipeWire, Flatpak and driver checks still run normally
• the CLI (wayland-spectre check) exits 0 on X11 when skips are the only non-passing results

Verified under a nested X server (Xephyr): 19 pass / 1 warn / 0 fail / 14 skip, exit code 0. The desktop entry also gained proper Categories=System;Monitor; in this release.

I have updated the PR to point at the v0.4.1 AppImage.

[probonopd]

Why, o why, doesn't the test system pick up which file got changed...

[probonopd]

I am sorry for the extra work, but please open a new PR. This is an issue with the test script.