v0.2.0 - wait for it

The "wait for it" release. 98 tests green on 3 OS x Python 3.9-3.14.

Added

• --wait [SECONDS] — block until the port is free (default 30s). Exit 0 once free, 3 on timeout. Replaces while ! whoseport 8080; do sleep 1; done loops in CI and restart scripts, and it works with --json too:

  whoseport 8080 --wait 60 && ./start-server.sh

• Terminal demo graphic in the README.
• Library usage documented: import whoseport; whoseport.collect(ports={8080}).

Fixed

• Backend failures during post-kill verification print a warning instead of a traceback.
• Ctrl+C exits cleanly with code 130.
• Grammar: "ports 3000, 8080" for multi-port kill summaries.
• CI: checkout v5 / setup-python v6 / upload-artifact v5 (Node 20 deprecation warnings gone).