Port the LinkSharing resource from /api/v1 to the Huma-backed /api/v2 under
/projects/{project}/shares. Self-registers via AddRouteRegistrar and is gated
on ServiceEnableLinkSharing, checked inside the registrar so a disabled
instance exposes no routes.
There is no update operation, mirroring v1: a share is created, read, listed
or deleted, never modified in place. Permissions stay at the model level via
the generic Do* handlers (project write to create read/write shares and to
delete; project admin to create an admin share and to list).
ReadOne is ported faithfully including a latent v1 quirk: CanRead resolves the
parent project from the share hash, which the by-id route never carries, so a
by-id read always 404s. The webtest pins this so a future fix is deliberate.
b107685063