Recognizes Vec3-shaped object schemas ({x, y, z} number properties)
structurally in RimWorkflowDescribeTools and dispatches them to a new
RimWorkflowVec3Binding in RimWorkflowTaskInput::createBinding(). Stores
the value as a cvf::Vec3d field, parses JSON object defaults, and emits
a YAML flow-mapping ({x: .., y: .., z: ..}) matching the taskmaestro
Vec3 pydantic model shape.