refactor: extract device registry and protocol from canvas.py

[danielislas3]

What

Move the master device list (206 entries) and category sets from canvas.py into a standalone device_registry module, and define device protocols.

Why

• The device list and category metadata are static data with no Qt dependency, but live inside a 19K-line canvas.py
• Extracting them enables tooling, tests, and eventual SDK usage without instantiating the full application
• 30+ machine drivers (KaleidoPort, Santoker, Orbiter, etc.) all implement the same implicit interface — now documented as RoasterProtocol

Files

File	Change
artisanlib/device_registry.py	New — 206-device list, 5 category sets, DEVICE_INFO dict, helper functions
artisanlib/device_protocol.py	New — RoasterProtocol, ScaleProtocol
artisanlib/canvas.py	Modified — imports from device_registry instead of ~400 inline lines
artisan.pro	Modified — 2 new source files

Verification

• ruff ✅
• pylint 10/10 ✅
• mypy ✅
• pyright 0 errors ✅
• pytest 2252 passed, 0 failed ✅

Zero behavior change.