CLASS-16: MEP equipment decoders (Electrical/Mechanical/Plumbing fixtures)

[DrunkOnJava]

Problem

MEP fixtures (ElectricalFixture, LightingFixture,
MechanicalEquipment, PlumbingFixture, SpecialtyEquipment) are
not decoded. Required for MEP-discipline real-project parity.

Scope

• Identify ElemTable tuples for each MEP category.
• Decode FamilyInstance dimensions + connector geometry where
  available (full route geometry deferred).
• Emit IFCFLOWFITTING / IFCFLOWTERMINAL / IFCDISTRIBUTION-
  ELEMENT per IFC4 mapping.

Acceptance criteria

• At least 1 IFC entity emitted per MEP category present in
  an MEP-discipline corpus fixture (Gate B requirement).
• MEP route geometry explicitly deferred and labeled in
  diagnostics.

Related

• Required for ROADMAP Gate B (MEP corpus expansion)
• Per TODO-BLINDSIDE Phase 4 L5B-36/L5B-37