Two messaging fixes: Header.parse and the project envelope

[gonzalocasas]

Two independent bug fixes on top of the Model migration. Neither involves a design decision.

Header.parse scrambles every field

messages.py is identical on main and restructure, so this fix applies to both. It lives here, at the base of the messaging stack, rather than in a separate PR against main: the protobuf wire work in #26 stacks on top of it and touches the same file, and #23 is queued to merge, so main picks the fix up along with it.

Header.parse passed four values positionally into a constructor whose first parameter is increment_response_ID, shifting every field. Broken since 2024-05-01. Fixed with keyword arguments, the dropped validation restored, plus a zero-valued-counter bug (sequence_id or default discards a legitimate 0).

The project envelope drops elements for timber models

create_project_data_from_compas emitted beams/joints instead of elements for a TimberModel:

if isinstance(model, TimberModel):
    data = {..., "beams": ..., "joints": ...}   # no "elements"
else:
    data = {..., "elements": ...}

Consumers read model and elements — the C# runtime does exactly that — so a timber project silently produced a model with no elements at all.

The envelope is now defined in terms of a plain compas_model Model and always emits elements. Beams and joints stay available for timber-aware consumers, but as additive extras rather than a different contract. This follows the intent that COMPAS XR work with plain Model by default and treat compas_timber as a specialisation.

Fully removing the compas_timber dependency is a larger job and not attempted here — BuildingPlan, Step and SimpleSequenceGenerator run through the project API.

Also

Relaxes the compas_pb test pin from 1.1 to 1.x, matching requirements.txt (>=1.1,<2) and the 1.2 the C# runtime targets. The test asserted 1.1. specifically and would have failed on a legitimate, wire-compatible upgrade.

15/15 tests pass.

🤖 Generated with Claude Code

[jckenny59]

LGTM 👍 Thanks for fixing my “creative interpretation” of Header.parse 😅