[FXC-5449] allow varying refinements on axisymmetric body faces

[alexxu-flex]

Note

Medium Risk
Modifies meshing parameter schema/serialization and volume-meshing translation for AxisymmetricBody refinements; mistakes could change generated mesh spacing or break backward/round-trip compatibility.

Overview
Adds per-segment spacing overrides for UniformRefinement on AxisymmetricBody via a new AxisymmetricSegment key type and optional face_spacing mapping.

Updates volume-meshing translation to emit dense faceSpacings arrays for axisymmetric bodies (derived from sparse overrides) while keeping other entity refinements unchanged, and adds contextual validation plus round-trip/translator tests for the new behavior.

Generalizes Flow360BaseModel.preprocess recursion to handle nested dict structures (in addition to lists/models) for unit conversion and preprocessing.

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[benflexcompute]

This is too nested and confusing. We need to redesign the interface.

[alexxu-flex]

//User interface
face_spacing={
axisymmetric_body.segments[1] : 0.2*fl.u.cm
}
// Storage side
"face_spacing":{
("entioty_id":"$axisymmetric_body.private_attribute_id", "segment_index": 1) : {"value": 0.2, "units":"cm"}
}

[alexxu-flex]

Then you need a Pydantic model for the "segment" class.

It will be similar relationship between Windtunnel farfield and the windtunnel ghost surfaces.

class Segment(BaseModel):
    type_name:Literal["Segment"]
    entity_id:str
    segment_index: int =pd.Field(min=..., )

[benflexcompute]

Face will be reserved for geometry concepts. It is a reserved word.

[benflexcompute]

Let's not use before validators unless really necessary.

Why don't we do this instead?

    face_spacing: Optional[Dict[AxisSymmetricSegment, LengthType.Positive]] = pd.Field(

And then we have:

class AxisSymmetricSegment(Flow360BaseModel):
    entity_id: str
    segment_index: pd.PositiveInt

so the axisymmetric_body.face(2) returns an AxisSymmetricSegment instance?

Then we do not need this complicate and fragile before validator?

[benflexcompute]

make this a contextual validator. You can then retrieve the axisymmetric body instance by querying the entity registry.

Take a look at param_info.get_entity_registry() and registry.find_by_type_name_and_id()

[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

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