`_raw_read_blocking` decoded the CBOR body and kept it only when it was a
Property map, so a Collection -- which answers the `[devcol rep, {href,
rep}, ...]` batch `parse_device0_batch` reads -- came back as `2.05` with
`rep: {}`. That renders as "the resource exists and has nothing in it",
which is the opposite of what a populated batch means, and `/device/0`
itself would have read the same way.
It cost a real result: issue #335's board answers `/sec/devices` (the
`x.com.samsung.devcol` sibling of `/device/0`, and the one remaining place
a composite appliance could be enumerating its indoor units) with exactly
that empty-looking 2.05, and it was nearly written off as a dead end.
The read path now returns the decoded body alongside `rep`, and the service
response carries it as `body` whenever it isn't the map `rep` already has --
omitted for the ordinary case rather than duplicating every rep in every
response. Records the probe round this came out of: indexed leaves 4.04 on
that board, and the UUID prefix confirmed routable by a positive control, so
Patterns A/B/C are ruled out there on evidence rather than on absence.