fix: alert banner — 'Spiega' button and title layout

- explainBannerAnomaly: querySelector('#alert-banner .banner-detail')
  was wrong (class is 'alert-banner-detail'); function returned null → no-op.
  Fixed to getElementById('alert-banner-detail').
- alert-banner-inner: position close button absolutely (top:10px right:10px)
  so it is removed from the flex row and can never push the title-body to
  collapse or wrap under it. Inner gets padding-right:44px to reserve space.
- alert-banner-body: flex:1 1 0 + overflow:hidden for robust sizing
- alert-banner-title: word-break/overflow-wrap so very long product names
  wrap cleanly inside the body instead of overflowing

assets/css/style.css

@@ -4915,7 +4915,8 @@ body.cooking-mode-active .app-header {
     display: flex;
     align-items: flex-start;
     gap: 10px;
-    padding: 12px 12px 8px;
+    padding: 12px 44px 8px 12px; /* right pad reserves space for abs-positioned close btn */
+    position: relative;
 }
 .alert-banner-icon {
     font-size: 1.5rem;
@@ -4923,14 +4924,17 @@ body.cooking-mode-active .app-header {
     line-height: 1;
 }
 .alert-banner-body {
-    flex: 1;
+    flex: 1 1 0;
     min-width: 0;
+    overflow: hidden;
 }
 .alert-banner-title {
     font-weight: 700;
     font-size: 0.95rem;
     color: #92400e;
     line-height: 1.3;
+    word-break: break-word;
+    overflow-wrap: break-word;
 }
 .banner-prediction .alert-banner-title {
     color: #5b21b6;
@@ -4942,7 +4946,9 @@ body.cooking-mode-active .app-header {
     line-height: 1.4;
 }
 .alert-banner-close {
-    flex-shrink: 0;
+    position: absolute;
+    top: 10px;
+    right: 10px;
     width: 28px;
     height: 28px;
     border-radius: 50%;
@@ -4954,6 +4960,7 @@ body.cooking-mode-active .app-header {
     align-items: center;
     justify-content: center;
     color: #78716c;
+    z-index: 1;
 }
 .alert-banner-actions {
     display: flex;