EnumishLabel
Overrides the label of the annotated leaf declaration.
value becomes the final label as-is; no LabelCase conversion is applied. Typical uses are resolving a label clash between leaves, and keeping persisted labels stable when a leaf is renamed.
Checked at compile time: only leaf declarations (the origin of a label) may carry this annotation, and blank values are rejected.
The retention is AnnotationRetention.BINARY for the same reason as Enumize.