fix(linux): use OnDemand GPU policy for AMD/Intel Mesa

WebKitGTK 6.0 removed WEBKIT_HARDWARE_ACCELERATION_POLICY_ON_DEMAND, so Wails maps OnDemand to ALWAYS. Never (the old Nvidia/X11 blank-window workaround) forces CPU raster on the GTK4/WebKit 6 stack. All target machines are AMD or Intel, where the Nvidia DMABUF workaround is unnecessary, so let the GPU handle scrolling/compositing.

main.go

@@ -47,7 +47,12 @@ func main() {
 		Linux: application.LinuxWindow{
 			Icon:                []byte("./build/AniTrack.png"),
 			WindowIsTranslucent: false,
-			WebviewGpuPolicy:    application.WebviewGpuPolicyNever,
+			// OnDemand: GPU for scrolling/compositing on AMD/Intel Mesa,
+			// software fallback otherwise. Never (the old Nvidia/X11
+			// blank-window workaround) forces CPU raster on GTK4/WebKit 6
+			// and makes scrolling janky. All target machines here are
+			// AMD or Intel, so the Nvidia DMABUF workaround is not needed.
+			WebviewGpuPolicy: application.WebviewGpuPolicyOnDemand,
 		},
 	})