fix(store): replace pinnedViews with ZStack overlay to prevent EXC_BAD_ACCESS crash

pinnedViews + rapid state changes from stretchAmount every frame during overscroll
triggers SwiftUI memory corruption. ZStack overlay approach is crash-free:
- LazyVStack with no pinnedViews
- Inline tabs fade out when pinned threshold reached
- Overlay tabs (with safeAreaTop padding) fade in at top of ZStack

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

@@ -46,17 +46,24 @@ struct StoreDetailView: View {
     let coverVisibleUntilY: CGFloat = 253
     let storeLogoSize: CGFloat = 84
 
+    var safeAreaTop: CGFloat {
+        #if canImport(UIKit)
+        return UIDevice.appSafeAreaTop
+        #else
+        return 0
+        #endif
+    }
+
     var body: some View {
         ScrollViewReader { proxy in
+            ZStack(alignment: .top) {
                 ScrollView(showsIndicators: false) {
                     ScrollOffsetReader(offsetY: $scrollOffset)
-                LazyVStack(spacing: 0, pinnedViews: [.sectionHeaders]) {
+                    LazyVStack(spacing: 0) {
                         topSection
-                    Section {
+                        categoryTabs(proxy: proxy, isPinned: false)
+                            .opacity(isCategoryTabsPinned ? 0 : 1)
                         sectionedProducts
-                    } header: {
-                        categoryTabs(proxy: proxy, isPinned: isCategoryTabsPinned)
-                    }
                     }
                 }
                 .coordinateSpace(name: StoreDetailScrollCoordinateSpace.name)
@@ -65,6 +72,13 @@ struct StoreDetailView: View {
                 }
                 .ignoresSafeArea(edges: .top)
                 .background(AppColors.backgroundLight)
+
+                categoryTabs(proxy: proxy, isPinned: true)
+                    .opacity(isCategoryTabsPinned ? 1 : 0)
+                    .allowsHitTesting(isCategoryTabsPinned)
+                    .zIndex(10)
+            }
+            .ignoresSafeArea(edges: .top)
             .saturation(isStoreOpen ? 1 : 0)
         }
         .navigationBarBackButtonHidden(true)