--json was folded into Quiet, which pinned the stderr log level to WARN.
So `prune --json` gave a machine consumer no record of the local index
rows it deleted, even under --verbose: the audit records were gated off
stdout and pinned below the level on stderr.
--json now quiets only the stdout UI, keeping the JSON document clean
(issue #108); the stderr log level follows --verbose/--debug again, since
diagnostics have gone to stderr since #82. The same coupling is removed
for `snapshot verify`, `snapshot remove`, and `remote info`, which
carried it for the same outdated reason.
A test asserts `--verbose prune --json` emits the cleanup record on
stderr while stdout stays exactly one document, and that --json alone
keeps it below the level.
model: claude-opus-4-8
