Hold a fatal error on the framebuffer and reboot in five minutes rather than exiting, since init's death drops the kernel's panic screen over the cause

fb.go

@@ -268,7 +268,10 @@ func openFramebuffer() (*framebuffer, error) {
 		return nil, fmt.Errorf("set crtc: %w", err)
 	}
 
-	go fb.readEvents()
+	go func() {
+		defer holdPanic()
+		fb.readEvents()
+	}()
 	// Nothing has been flipped yet, so the first frame is owed its turn.
 	fb.flips <- struct{}{}
 	return fb, nil