fix: improve endgame clock and gameplay stability

internal/sdkserver/hotfix_cache_test.go

@@ -0,0 +1,20 @@
+package sdkserver
+
+import (
+	"os"
+	"testing"
+)
+
+func TestLoadHotfixIgnoresEmptyCacheWhenBundledEntryExists(t *testing.T) {
+	t.Chdir(t.TempDir())
+	if err := os.WriteFile("hotfix.json", []byte(`{"bundled":{"asset_bundle_url":"bundle"},"override":{"asset_bundle_url":"old"}}`), 0600); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile("versions.json", []byte(`{"bundled":{},"override":{"asset_bundle_url":"user"},"cached":{"asset_bundle_url":"cached"}}`), 0600); err != nil {
+		t.Fatal(err)
+	}
+	got := loadHotfix()
+	if got["bundled"].AssetBundleURL != "bundle" || got["override"].AssetBundleURL != "user" || got["cached"].AssetBundleURL != "cached" {
+		t.Fatalf("incorrect hotfix cache merge: %+v", got)
+	}
+}