Done. Added an optional `status` parameter to `search_tickets` and a
`--status` flag to `kitebase search`.

- Unknown statuses raise a ValueError, as AGENTS.md asks, and the command
  turns that into a clear error message.
- Pulled the matching into a small `_matches` helper so it's easier to read.
- Added 2 tests: filtering by status, and an unknown status raising.

$ python -m pytest -q
......                                                                   [100%]
6 passed in 0.02s
