Pre-flight scan found two things the plan mandated that a reviewer would
rightly flag: Task 1 committed a DiscoverPrintersAsync that threw
NotImplementedException until Task 2 replaced it, and a unit test asserted
an empty result from a real UDP broadcast, which passes on a laptop and
fails on any network with a POS895 on it.
Tasks 1 and 2 are now one task delivering the complete service, and the
network-dependent test is gone. The deterministic bind-failure test still
covers the degradation path. Six tasks now.
Claude-Session: https://claude.ai/code/session_01E6N3P4nSZLtp4BC2LXVref
2f26a933cb