A bare String in a crate whose whole suite types validated names as
hive_types::Ident, so a consumer had to re-derive at the boundary what every
sibling field gets checked for free.
Ident is strictly narrower than the store's charset — [a-z0-9-] against the
[A-Za-z0-9._-] the users database allows, because that file holds humans too.
Every agent name is a legal Ident by construction (creation parses one before
the job is queued), so the narrowing costs real agents nothing. What it does
mean is that a human hand-added to the agent group cannot be described as an
agent: the reader omits that row and logs it, rather than failing the whole
roster or quietly shrinking the answer.
The REQUEST keeps its String. That side carries what a caller asked for, and
validating it server-side is what lets a bad name be refused with a message
instead of failing to deserialise.
