provider

type Provider interface {
	// Get retrieves the current raw value for a key from the backend.
	Get(ctx context.Context, key string) (string, error)

	// Watch monitors multiple keys for changes. The provider is free to
	// implement this as a single prefix watch, a batch poll, or any other
	// efficient strategy. When a change is detected for a key, onChange is
	// called with the key and the new raw string value.
	// The implementation must block until the context is cancelled or an error occurs.
	Watch(ctx context.Context, keys []string, onChange func(key string, value string)) error

	// Close releases any resources held by the provider.
	Close() error
}