fix: improve endgame clock and gameplay stability

internal/common/persistent_store.go

@@ -157,6 +157,59 @@ func SaveAvatarRank(id, rank uint32) error {
 	return SaveAvatarProgress(id, nil, &rank)
 }
 
+// MaxAvatarProgress updates the latest roster under the shared save lock,
+// preserving unknown fields and all non-avatar data.
+func MaxAvatarProgress() (int, error) {
+	persistentWriteMu.Lock()
+	defer persistentWriteMu.Unlock()
+	unlock, err := lockPersistentFile()
+	if err != nil {
+		return 0, err
+	}
+	defer unlock()
+	raw, err := os.ReadFile("freesr-data.json")
+	if err != nil {
+		return 0, err
+	}
+	var root map[string]json.RawMessage
+	if err = json.Unmarshal(raw, &root); err != nil || root == nil {
+		return 0, fmt.Errorf("invalid freesr-data object")
+	}
+	var avatars map[string]json.RawMessage
+	if err = json.Unmarshal(root["avatars"], &avatars); err != nil || avatars == nil {
+		return 0, fmt.Errorf("invalid avatar roster")
+	}
+	for id, entry := range avatars {
+		var avatar map[string]json.RawMessage
+		if err = json.Unmarshal(entry, &avatar); err != nil || avatar == nil {
+			return 0, fmt.Errorf("invalid avatar %s", id)
+		}
+		var data map[string]json.RawMessage
+		if err = json.Unmarshal(avatar["data"], &data); err != nil || data == nil {
+			return 0, fmt.Errorf("invalid rank data for avatar %s", id)
+		}
+		avatar["level"] = json.RawMessage("80")
+		avatar["promotion"] = json.RawMessage("6")
+		data["rank"] = json.RawMessage("6")
+		avatar["data"], err = json.Marshal(data)
+		if err != nil {
+			return 0, err
+		}
+		avatars[id], err = json.Marshal(avatar)
+		if err != nil {
+			return 0, err
+		}
+	}
+	root["avatars"], err = json.Marshal(avatars)
+	if err != nil {
+		return 0, err
+	}
+	if err = writeJSONAtomic("freesr-data.json", root); err != nil {
+		return 0, err
+	}
+	return len(avatars), nil
+}
+
 // SaveAvatarProgress patches only the selected level and/or rank in the latest
 // import, under the same cross-process lock used by inventory and gacha saves.
 func SaveAvatarProgress(id uint32, level, rank *uint32) error {