fix(store): pin all non-image elements during overscroll bounce

Apply offset(y: -stretchAmount) to gradient, buttons, summaryCard, storeLogoBadge, and hard-cut rectangle so only the cover image stretches on pull-down

pedi-foods/Sources/PediFoods/Views/Main/StoreDetailView+Components.swift

@@ -11,14 +11,16 @@ extension StoreDetailView {
             Rectangle()
                 .fill(AppColors.backgroundLight)
                 .frame(height: max(0, topSectionHeight - coverVisibleUntilY))
-                .offset(y: coverVisibleUntilY)
+                .offset(y: coverVisibleUntilY - stretchAmount)
 
             summaryCard
                 .padding(.horizontal, 16)
                 .padding(.top, cardTopInset)
+                .offset(y: -stretchAmount)
 
             storeLogoBadge
                 .padding(.top, cardTopInset - (storeLogoSize / 2))
+                .offset(y: -stretchAmount)
         }
         .frame(height: topSectionHeight)
     }
@@ -37,6 +39,7 @@ extension StoreDetailView {
             )
             .frame(height: topSectionHeight)
             .ignoresSafeArea(.container, edges: .top)
+            .offset(y: -stretchAmount)
             .allowsHitTesting(false)
 
             VStack(spacing: 0) {
@@ -66,6 +69,7 @@ extension StoreDetailView {
                     .foregroundStyle(Color.white.opacity(0.92))
                     .padding(.bottom, 14)
             }
+            .offset(y: -stretchAmount)
         }
     }