Seven TDD tasks derived from the design spec, each ending in a commit: test project and SPRT protocol parsing, the discovery network path, CompositeDiscoveryService, the POS895 adapter, the three switch registrations, the nullable printer-id guard, and DI wiring plus an emulated POS895. Claude-Session: https://claude.ai/code/session_01E6N3P4nSZLtp4BC2LXVref