Track @thermal-label/contracts 0.5.0 and the 0.5.0 baseline of the
brother-ql / labelmanager / labelwriter -node drivers. Peer ranges
bumped to >=0.5.0.

Inlines a local discoverAll helper in src/discovery.ts so the CLI no
longer pulls @thermal-label/transport just for one Promise.allSettled
fan-out — list and select now import discoverAll from the local module.
Tests adjusted to the new import surface.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>