fix: 配方卡片总成本条和底部行恢复全宽，预览与实际一致

- card-content padding-right:80px 给QR留空间
- card-total 和 card-bottom-row 用 margin-right:-80px 抵消padding
  恢复全宽显示（总成本条和日期行不被QR挤压）
- 预览图和实际卡片布局验证一致

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/components/RecipeDetailOverlay.vue

@@ -1122,7 +1122,7 @@ async function saveRecipe() {
 .card-content {
   position: relative;
   z-index: 2;
-  padding-right: 70px; /* leave room for QR */
+  padding-right: 80px; /* leave room for QR (54px) + gap */
 }
 
 /* Brand overlays */
@@ -1180,6 +1180,8 @@ async function saveRecipe() {
   justify-content: space-between;
   align-items: flex-end;
   margin-top: 16px;
+  margin-right: -80px; /* counteract card-content padding-right to span full width */
+  padding-right: 0;
 }
 
 .card-brand-text {
@@ -1278,6 +1280,7 @@ async function saveRecipe() {
   justify-content: space-between;
   align-items: center;
   margin-top: 8px;
+  margin-right: -80px; /* counteract card-content padding-right */
 }
 
 .card-total-label {