Extract MockSkyWalker1 to shared mock_device.py (used by both unit tests
and server lifespan). Server checks SKYWALKER_MOCK env var at startup —
when set, uses mock device instead of USB hardware, enabling full MCP
transport testing via claude -p without the dongle connected.
Verified: 64 unit tests pass, claude -p integration tests exercise
identify_frequency, get_device_status, and sweep_spectrum through the
complete JSON-RPC pipeline.
Ryan Malloy
cbfbbf6bfe