- buildPier builds on buildAxis: each object carries its stretch k and a local
s from that stretch's base; coping parts are per stretch with the mitre plane
trimming the overlap in the scene (renderer.localClippingEnabled).
- Straight P1 output is unchanged (regression tests pass).
- Bent coping is supported for 현장타설말뚝 only; footings and piles on a bent
axis remain 미실시 until stage 3. Kink outside the coping and columns within
the Level half-width of the kink are refused.
- W03/W04 use coping coordinates (g).
- Tests: constructed 60° bend — world coordinates of bearings, blocks and the
column survive the stretch frames; mitre sides; scene mesh count; refusals.
Co-Authored-By: Claude Haiku 5.5 <noreply@anthropic.com>