fix(view): solplate reference shows centre T = 30 with the (−) and (+) side thicknesses (taper along the axis)

The solplate tapers along the bridge axis. T is the centre thickness (30), T1 the thickness on the 교각축 직각 (−) side
(38) and T2 on the (+) side (22); T1 + T2 = 2T. The table's T column had shown the (−) side value, so T is now 30 on every
row. A test checks T1 + T2 = 2T.

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

src/main.ts

@@ -1280,7 +1280,7 @@ function renderBearingRef(box: HTMLDivElement, pier: Pier): void {
   const st = el('table', undefined, 'grid-table rebar-table');
   const sh = el('thead');
   const shr = el('tr');
-  for (const h of ['No', 'S (%)', 'L', 'W', 'T', 'T1', 'T2', '식 검산']) shr.appendChild(el('th', h));
+  for (const h of ['No', 'S (%)', 'L', 'W', 'T (중심)', 'T1 (−측)', 'T2 (+측)', '식 검산']) shr.appendChild(el('th', h));
   sh.appendChild(shr);
   st.appendChild(sh);
   const sb = el('tbody');