OutdoorUnit and Controller model_sku not being deserialized from API

[eman]

Problem

When using quilt-hp-python to deserialize system snapshots from the Quilt API, the model_sku field is None or empty for:

• OutdoorUnit devices
• Controller devices (dials)

In contrast, IndoorUnit devices correctly populate their model_sku values.

This causes Home Assistant devices to display fallback names like "Quilt Outdoor Unit" and "Quilt Dial" instead of the actual product SKU (e.g., "QHP-1234").

Investigation Findings

After debugging with v0.2.2, I confirmed:

1. The fallback logic is working correctly - when model_sku is None, fallbacks display properly
2. The root cause is model_sku being None/empty - not a consumer integration issue
3. IndoorUnit works correctly - suggesting selective deserialization issue
4. No fix in v0.2.2 - checked commits v0.2.1..v0.2.2; no changes to hardware map deserialization

Desired Behavior

OutdoorUnit.from_proto() and Controller.from_proto() should correctly deserialize the model_sku field from the API's protobuf outdoor_unit_hardware and controller_hardware fields, matching the behavior of IndoorUnit.

Next Steps

This likely involves:

• Verifying the API is returning the hardware fields in snapshots
• Checking if quilt-hp-python is correctly extracting hardware info from the protobuf message
• Ensuring stream updates preserve the model_sku value (not overwriting with None)

Would appreciate guidance on where the deserialization might be failing so we can debug further or provide a fix.