OpenBao checks a LIST against the directory with a trailing slash, so
the controller's LIST on secret/metadata/swarm/agents/<a>/matrix is
checked as .../matrix/. Its empty last segment matches the `+` in the
delete stanza .../agents/+/matrix/+ (added by bbf93120), which then is
the only non-exact rule matching, and its ["delete"] denies the LIST
before acl.go's trimmed-path fallback reaches .../+/matrix ["list"].
The forge directory fails the same way against .../+/forge/+.
Writing the list stanzas as .../+/matrix/ and .../+/forge/ makes them
match the slashed request too, and with one `+` segment against two
they outrank the delete stanzas. Deletes on .../matrix/<id> still
resolve to .../+/matrix/+, which the slashed list path does not match.
Reproduced by iris against a local bao server -dev with a non-root
token: list stanza alone allowed, plus the delete stanza denied, list
stanza with trailing slash plus the delete stanza allowed.
Closes#4919