Create a taxonomy axis (axe de classification)
Creates one classification axis under a caller-supplied id, optionally with an initial node tree (roots defaults to empty). 409s when the id already exists; 400s on a bad scope/source enum or an empty name.
Authorizations
Authorization: Bearer <token>. Accepts EITHER a Keycloak access token (scopes-in-token) OR an opaque POS session token; both resolve to the same pos.* scope vocabulary the route guards enforce.
Body
Caller-supplied axis id (must be unique).
1Display name of the axis (e.g. Couleur, Famille).
1What the axis classifies: product, variant (builds SKU-group labels), or movement.
product, variant, movement Origin of the axis values: managed, local, or an external feed.
managed, local The initial node tree (unbounded depth); defaults to empty.

