feat(view): solplate taper across the 교각축 직각 (thick T1 at the (−) side); 교량받침 본체 as a box

The solplate's L (A + margin) runs across the 교각축 직각 and its W (B + margin) along the 교축; the top tapers across L with
T1 at the (−) side (T1 = T + L·|S|/200). The 교량받침 본체 is one box per bearing: the solplate plan less 100 mm on each
side, from the mortar top (EL.X) up h3 = 181 mm, turned with the bearing row. It is shown with the bearing group.

Co-Authored-By: Claude Haiku 5.5 <noreply@anthropic.com>

src/core/solplate.ts

@@ -1,12 +1,13 @@
 /**
- * 솔플레이트 기하 (1단계, 승인 2026-10-23). Pure: the solplate of one bearing, from its block (position, rowSkew) and the
- * 공통 규칙 values. The solplate sits on the bearing (h3) and tapers along the 교축 방향 (s): the thick end T1 is on the
- * 시점 side (s = −L/2), the thin end T2 on the 종점 side (s = +L/2). Lengths in m, as in the model.
+ * 솔플레이트 기하 (승인 2026-10-23). Pure: the solplate of one bearing, from its block (position, rowSkew) and the
+ * 공통 규칙 values. The plan is L = A + margin across the 교각축 직각 (n) and W = B + margin along the 교축 (s). The top
+ * tapers across L: the thick end T1 is at the (−) side of the 교각축 직각 direction (n = −L/2), the thin end T2 at (+) (n = +L/2).
+ * The underside is the bearing top (block top EL.X + h3). Lengths in m, as in the model.
  */
 import { blockFramePoint, type BlockModel } from './geometry';
 
 export interface SolplateParams {
-  /** 받침 평면 A (mm, along 교축 s) and B (mm, along the 교각축 직각 n). */
+  /** 받침 평면 A (mm, across the 교각축 직각) and B (mm, along the 교축). */
   A: number;
   B: number;
   /** 솔플 여유 (mm): L = A + margin, W = B + margin. */
@@ -18,15 +19,15 @@ export interface SolplateParams {
 }
 
 export interface SolplateGeometry {
-  /** Length along 교축 (m) and width along 교각축 직각 (m). */
+  /** Length across the 교각축 직각 (m, = A + margin) and width along the 교축 (m, = B + margin). */
   L: number;
   W: number;
-  /** Thickness at the 시점 end (T1) and the 종점 end (T2) (m). */
+  /** Thickness at the (−) side (T1) and the (+) side (T2) of the 교각축 직각 direction (m). */
   T1: number;
   T2: number;
   /** Underside (EL m): the bearing top = block top (EL.X) + h3. */
   bottom: number;
-  /** Eight corners: [s, y, n] in the model's local frame (EL m). */
+  /** Eight corners: [s, y, n] in the model's local frame (EL m); order (a, c, bottom|top) with a along s and c along n. */
   corners: [number, number, number][];
   /** Volume (m³): L·W·(T1 + T2)/2. */
   volume: number;
@@ -34,21 +35,21 @@ export interface SolplateGeometry {
 
 /** Solplate of the bearing at `block`, with the bearing height h3 (mm) and the 공통 규칙 parameters. */
 export function solplateGeometry(block: BlockModel, h3: number, p: SolplateParams): SolplateGeometry {
-  const L = (p.A + p.margin) / 1000;
-  const W = (p.B + p.margin) / 1000;
-  // Thickness change from the centre to each end: L·|S|/2, with S in % (mm).
+  const L = (p.A + p.margin) / 1000; // across the 교각축 직각 (n)
+  const W = (p.B + p.margin) / 1000; // along the 교축 (s)
+  // Thickness change from the centre to each side: L·|S|/2, with S in % (mm).
   const drop = ((p.A + p.margin) * Math.abs(p.slopePct)) / 200 / 1000;
   const T = p.T / 1000;
   const T1 = T + drop;
   const T2 = T - drop;
   const bottom = block.padTop + h3 / 1000;
-  const thickAt = (a: number) => T1 + ((T2 - T1) * (a + L / 2)) / L;
+  const thickAt = (c: number) => T1 + ((T2 - T1) * (c + L / 2)) / L;
   const corners: [number, number, number][] = [];
-  for (const a of [-L / 2, L / 2]) {
-    for (const c of [-W / 2, W / 2]) {
+  for (const a of [-W / 2, W / 2]) {
+    for (const c of [-L / 2, L / 2]) {
       const [s, n] = blockFramePoint(block, a, c);
       corners.push([s, bottom, n]);
-      corners.push([s, bottom + thickAt(a), n]);
+      corners.push([s, bottom + thickAt(c), n]);
     }
   }
   return { L, W, T1, T2, bottom, corners, volume: (L * W * (T1 + T2)) / 2 };