With the backend on auto, Linux installed no adapter selector, so wgpu took
the first discrete GPU the driver listed. On a machine with an eGPU, a
laptop dGPU and an iGPU that was not the one the user wanted.
- performance.gpuAdapter: a case-insensitive piece of the adapter's name
(several words must all appear); empty is automatic.
- PHOTOCRAFT_GPU_ADAPTER overrides it for one launch.
- Preferences > Performance > Advanced > GPU adapter lists the adapters the
instance found; a saved adapter that is absent stays listed, marked.
- A missing adapter, or one that can't present to the window, falls back to
the automatic choice with a note in System Info. CPU mode ignores it.
- Shown on Linux only; tested on Linux only. Windows and macOS need their own
work (the startup code honours the setting there, but it is untested).
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
