Script: add a 'count' subcommand (POST /search/approximate-count) and a
'transitions' discovery subcommand, plus --resolution on transition
(satisfies Done-screen requirements in one call), offset-paginated
fetches for --max > 50 with empty-page termination when total shrinks,
parsed API error envelopes (errors map + errorMessages) instead of raw
dumps, and 429 handling surfacing Retry-After/RateLimit-Reason. Existing
flags, --json/--dry-run, and subcommands preserved; stdlib+requests only.
Tests: 20-case offline suite (help output, argument errors, dry-run
plans, mocked-client pagination/error/transition logic) passing pytest
and unittest runners including the proxy-trap zero-egress rerun.
Co-authored-by: factory-droid[bot] <138933559+factory-droid[bot]@users.noreply.github.com>
