generate_annotation built the annotation list from a set union and sorted it by
ZIndex and TEXT-ness only. Annotations that tied on that key kept set iteration
order, which follows entity hash (step id plus the process memory address), so
the order of tied annotations (for example a label and its background fill)
shuffled between Blender restarts and flipped their draw order.
Add the stable IFC step id as a final tiebreaker so the order is total and
session independent. Behavior preserving, no z-layer semantics changed.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
(cherry picked from commit d30286225c)
Petru Conduraru
c2b168b45b