Fix Gemini candidate cap causing search 500s

backend/services/cse_test.go

@@ -63,3 +63,9 @@ func TestIsRenderableArtgridResultAcceptsArtlistCanonical(t *testing.T) {
 		t.Fatal("expected artlist canonical clip URL to be accepted for Artgrid collector")
 	}
 }
+
+func TestGeminiCandidateLimitNeverExceedsCandidates(t *testing.T) {
+	if got := GeminiCandidateLimit(9); got != 9 {
+		t.Fatalf("expected Gemini limit to stay within candidate count, got %d", got)
+	}
+}