RE-15-10: Decode real space boundaries from 2024 (replace 10x10x8 ft placeholder bbox)

[DrunkOnJava]

Problem

v0.2.0 emits 50 IFCSPACE entities with placeholder 10x10x8 ft
bounding-box geometry regardless of actual room dimensions.
BlenderBIM space-overlay rendering is meaningless as a result.

Scope

• Decode space boundary loop (sequence of curves) from the
  Space partition record bytes.
• Build IfcExtrudedAreaSolid with the real polygon profile
  and the floor-to-ceiling height (from level elevations).
• Preserve degenerate-boundary cases as diagnostic warnings,
  not silent placeholder fallback.

Acceptance criteria

• At least 30 spaces in 2024_Core_Interior.rvt carry real
  polygon geometry instead of bbox.
• Visual diff against Revit's IFC export shows matching shape
  for at least 5 named rooms (depends on RE-15-06 for names).
• Diagnostic count of degenerate boundaries reported.

Related

• Builds on RE-15-04 (recall lift)
• Blocks: viewer Room overlay