One component per file; GAME OVER offers CONTINUE

PRD G1 asks for one component per file. Eight files held two or
three; their eleven extra components move to files of their own,
helpers stay where both sides use them, and an archtest now fails
any file that holds two.

PRD 4.4 and the request say an error always offers CONTINUE.
ErrorState's button read RETRY; it now reads CONTINUE, under the
CONTINUE? countdown, on the crash screen and the lost page alike.

gallery/app_test.go

@@ -123,10 +123,10 @@ func TestLostPageAndLocale(t *testing.T) {
 		t.Fatalf("lost page texts %q", tt.Texts())
 	}
 	click(t, tt, "language")
-	if a.locale != pixel.Zh || !tt.HasText("重试") {
+	if _, ok := tt.Find("继续"); a.locale != pixel.Zh || !ok {
 		t.Fatal("language toggle did not switch built-in copy")
 	}
-	click(t, tt, "重试")
+	click(t, tt, "继续")
 	if a.Path() != "/" {
 		t.Fatalf("continue went to %q", a.Path())
 	}

gallery/demos_feedback.go

@@ -20,7 +20,7 @@ var feedbackEntries = []Entry{
 	{110, "Alert", "提示框", "feedback", "A framed callout: info, success, warning or danger, with an optional ×.", demoAlert},
 	{111, "Banner", "横幅", "feedback", "A full-width strip with actions and a ×.", demoBanner},
 	{112, "EmptyState", "空状态", "feedback", "NO ITEMS over an empty chest, and something to do about it.", demoEmptyState},
-	{113, "ErrorState", "错误态", "feedback", "GAME OVER, a CONTINUE? countdown and RETRY. The gallery's own errors use it.", demoErrorState},
+	{113, "ErrorState", "错误态", "feedback", "GAME OVER, a CONTINUE? countdown, and CONTINUE. The gallery's own errors use it.", demoErrorState},
 	{114, "SuccessState", "通关", "feedback", "STAGE CLEAR! The stars pop in one by one.", demoSuccessState},
 	{115, "LoadingScreen", "加载画面", "feedback", "NOW LOADING with stepping dots and a tip every four seconds.", demoLoadingScreen},
 	{116, "DotsLoader", "点点加载", "feedback", "Three dots hopping in turn.", demoDotsLoader},