Two WMO rendering fixes:
1. Glass batch merging: BatchKey didn't include isWindow, so window and
non-window batches sharing the same texture got merged together. If
the window batch was processed first, the entire merged batch (lamp
base, iron frame, etc.) rendered as transparent glass. Add isWindow
to the batch key so glass/non-glass batches stay separate.
2. LOD group culling: WMO groups named with "LOD" are distance-only
impostor geometry (e.g. cathedral tower extension, hill tower). They
should only render beyond 200 units. Store raw MOGN chunk for
offset-based name lookup, detect "lod" in group names during load,
and skip LOD groups in both main and shadow passes when camera is
within range.