fix(linux): disable WebKit DMA-BUF renderer to prevent Wayland crash

[Charlisim]

Summary

On Nvidia GPUs running Wayland, WebKit2GTK's DMA-BUF renderer triggers a protocol error (71) due to an explicit sync conflict between WebKit's ANGLE implementation and Nvidia's egl-wayland library. This sets `__NV_DISABLE_EXPLICIT_SYNC=1` only when Nvidia drivers are active and a Wayland display is present, avoiding the crash without disabling hardware acceleration.

Submission

• This PR is a bug fix or small-scope improvement.
• If this PR is not a bug fix or small-scope improvement, I linked an approved feedback item below.
• I have read and followed CONTRIBUTING.md.
• I tested this change locally.
• I added or updated tests when reasonable.

Approved feedback item (required if not a bug fix or small-scope improvement):

Related

WebKit upstream bug: https://bugs.webkit.org/show_bug.cgi?id=280210

[gschier]

I've been avoiding doing this because I don't want to disable hardware acceleration for users that don't have this bug.

I've been thinking of maybe trying to catch the error by maybe setting a flag on launch and unsetting if the app actually showed a window. Then, next launch could check that flag and prompt the user with a native confirmation to set the flag for them.

[Charlisim]

Thanks for the feedback — that's a fair concern, and I looked into it further.

After digging into the upstream WebKit bug tracker, this issue is tracked at https://bugs.webkit.org/show_bug.cgi?id=280210. The root cause is specific to Nvidia GPUs on Wayland: there's an explicit sync conflict between WebKit's ANGLE implementation and Nvidia's egl-wayland library (wp_linux_drm_syncobj_surface_v1). It's not a general compositor issue.

That also means there's a more targeted workaround: __NV_DISABLE_EXPLICIT_SYNC=1 disables the explicit sync path on the Nvidia driver side without touching the DMA-BUF renderer itself, so hardware acceleration is preserved.

I've updated the PR to use that approach instead — the variable is only set when:

• We're on Linux
• A Wayland display is active (WAYLAND_DISPLAY is set)
• Nvidia drivers are loaded (/sys/module/nvidia exists)
• The user hasn't already set the variable themselves

Users on AMD/Intel are completely unaffected. Happy to adjust if you'd prefer a different detection strategy.