refactor: extract mqtt_demo/ — move bridge, config, logger, appliance descriptors

mqtt_demo/samples/__init__.py

@@ -0,0 +1,35 @@
+"""Appliance descriptors registry.
+
+Adding a new appliance class:
+  1. Write `appliances/<class>.py` with an ApplianceDescriptor named
+     after the class (uppercase, e.g. OVEN).
+  2. Add it to DESCRIPTORS below.
+  3. Set DEVICE_CLASS=<class> in the per-device .env.
+
+main.py imports get_descriptor(name) to look up the descriptor at
+startup; the bridge itself stays class-agnostic.
+"""
+from ..descriptor import ApplianceDescriptor
+from .dryer import DRYER
+from .oven import OVEN
+from .fridge import FRIDGE
+
+
+
+DESCRIPTORS: dict[str, ApplianceDescriptor] = {
+    DRYER.name: DRYER,
+    OVEN.name:  OVEN,
+    FRIDGE.name: FRIDGE,
+}
+
+
+def get_descriptor(name: str) -> ApplianceDescriptor:
+    try:
+        return DESCRIPTORS[name]
+    except KeyError:
+        raise ValueError(
+            f"unknown DEVICE_CLASS={name!r}; "
+            f"available: {sorted(DESCRIPTORS)}") from None
+
+
+__all__ = ['ApplianceDescriptor', 'DESCRIPTORS', 'get_descriptor']