CoreConfigManager
Minimal config manager that loads/saves text configs via a ConfigTextStore.
Versioning
This implementation stores configs as text and applies ConfigKey.migrations on the raw text. Version detection is intentionally simple and format-agnostic; it relies on a tiny convention:
The first non-empty, non-comment line may be:
ktaleConfigVersion: <int>
Platforms and plugins are free to ignore this convention and provide their own ConfigManager.