feat(view): the 열별 본수 card sits beside the footing plan on ② (grid, stacks on narrow screens)

The pile-count card (−/+ and the 20본 total) is on the left and the plan on the right, in one row; the side view is below.
Changing a count is now seen on the plan next to it. The layout stacks below 800 px.

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

src/style.css

@@ -799,3 +799,9 @@ body { background: #eef1f4; font-family: 'Noto Sans KR', system-ui, sans-serif;
 .footing-drawings { display: grid; gap: 10px; margin-top: 12px; }
 .footing-fig { margin: 0; }
 .footing-fig svg { width: 100%; height: auto; max-height: 260px; background: #ffffff; border: 1px solid #d5dde6; border-radius: 6px; }
+
+/* ② 말뚝 배치: 열별 본수 카드 (왼쪽) · 평면도 (오른쪽), 측면도는 아래 */
+.footing-grid { display: grid; grid-template-columns: minmax(230px, 320px) minmax(0, 1fr); gap: 12px; align-items: start; margin-top: 12px; }
+@media (max-width: 800px) {
+  .footing-grid { grid-template-columns: 1fr; }
+}