Launched with no --server, udpscope silently connects to 127.0.0.1:8000 and
offers no way to pick a source or see which ones it already knows. The design
is a pre-flight dialog: it runs before ScopeModel exists, so a cancel costs no
buffer and no socket and the existing pipeline is untouched.
The list is built from the stored session files, filtered to those naming at
least one signal -- a development machine accumulates one file per probe run on
a throwaway port, 140 of them here -- and the session format gains multicast and
interface keys so a row can reconnect exactly.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
