Update GaCy-GO

internal/common/persistent_patch.go

@@ -0,0 +1,34 @@
+package common
+
+import (
+	"encoding/json"
+	"fmt"
+)
+
+// Patch selected top-level fields against the latest file, under the same lock
+// used by game saves. Raw JSON retains 64-bit scores and unknown save sections.
+func PatchPersistentFields(patch map[string]json.RawMessage) error {
+	if patch == nil {
+		return fmt.Errorf("persistent patch must be a JSON object")
+	}
+	for _, raw := range patch {
+		if !json.Valid(raw) {
+			return fmt.Errorf("invalid persistent field JSON")
+		}
+	}
+	persistentWriteMu.Lock()
+	defer persistentWriteMu.Unlock()
+	unlock, err := lockPersistentFile()
+	if err != nil {
+		return err
+	}
+	defer unlock()
+	root, err := readCurrencyWarsPersistentRoot()
+	if err != nil {
+		return err
+	}
+	for key, value := range patch {
+		root[key] = value
+	}
+	return writeJSONAtomic("persistent", root)
+}