diff --git a/HANDOFF.md b/HANDOFF.md
index 52e1e73..d79d9ee 100644
--- a/HANDOFF.md
+++ b/HANDOFF.md
@@ -8,6 +8,12 @@ Latest verified commit: `f090ba7`
 
 This codebase has recent updates around auth/onboarding, help/privacy pages, dashboard search, product creation/edit/review/detail, admin review/detail, stock/price editing, seller in-review listing, backend request logging, expired-session redirects, product keyword limits, sanitized backend error display, AddProductRequest validation, and 10 MB upload limits.
 
+Latest local verification before the newest push:
+
+```bash
+npm run build
+```
+
 The latest build was verified successfully with:
 
 ```bash
@@ -20,6 +26,60 @@ Latest TypeScript verification after the validation/upload changes:
 npx tsc --noEmit
 ```
 
+## Latest Codex Changes After `2cfff02`
+
+### Product edit image payload preservation
+
+File:
+- `src/app/(dashboard)/products/[productId]/edit/page.tsx`
+
+Behavior:
+- Edit-product save keeps `imageId` as the main image field.
+- If the main image already exists inside `productImages`, the save payload preserves it at the same sequence.
+- If the main image is replaced, the old main image entry inside `productImages` is replaced with the new `imageId` at the same sequence.
+- The edit gallery UI hides duplicate thumbnails where `form.imageId` is also present in `form.productImages`, but the underlying array is preserved for payload sequence.
+
+Expected image payload shape:
+
+```json
+{
+  "imageId": "imageBaru.jpg",
+  "productImages": [
+    { "imageId": "gallery-0.jpg", "sequence": 1 },
+    { "imageId": "imageBaru.jpg", "sequence": 2 },
+    { "imageId": "gallery-2.jpg", "sequence": 3 }
+  ]
+}
+```
+
+### Product detail image gallery
+
+Files:
+- `src/app/(dashboard)/products/[productId]/detail/page.tsx`
+- `src/components/product-variant-showcase.tsx`
+- `src/lib/product-variants.ts`
+
+Behavior:
+- Product detail image thumbnails are deduplicated between root `imageId` and `productImages`.
+- Thumbnail strip is horizontally scrollable when there are many images.
+- Clicking a thumbnail updates the large preview image.
+- The active thumbnail receives a visible selected state.
+
+### Product submenu click lock fix
+
+Files:
+- `src/app/(dashboard)/layout.tsx`
+- `src/app/(dashboard)/products/page.tsx`
+- `src/components/product-submenu-nav.tsx`
+
+Behavior:
+- Product submenu items now use Next `<Link>` instead of manual `button` + `router.push`.
+- `All Product` now navigates to `/products?tab=all`, matching the query-based pattern used by the other submenu tabs.
+- Product API already normalizes `tab=all` to the all-product backend endpoint.
+- Sidebar z-index was raised above product modals so submenu clicks are not blocked by stale overlays.
+- Product list clears action-menu and modal state when tab/page changes.
+- Delete/unpublish/stock-price-load errors now close the related modal after showing the error, preventing a full-screen overlay from trapping sidebar clicks.
+
 ## Latest Codex Changes After `76fb4f3`
 
 ### Product create preorder and warranty submit rules
@@ -602,13 +662,13 @@ pm2 save
 sudo -iu inadev pm2 status
 ```
 
-Current expected deployed commit after latest push:
+Current expected deployed commit after latest push is the latest `origin/main` commit from this handoff update. Verify short hash with:
 
 ```bash
-2f64282
+git rev-parse --short HEAD
 ```
 
-Verify on server:
+Verify full commit on server:
 
 ```bash
 git rev-parse HEAD
diff --git a/src/app/(dashboard)/layout.tsx b/src/app/(dashboard)/layout.tsx
index d50864d..e9ca629 100644
--- a/src/app/(dashboard)/layout.tsx
+++ b/src/app/(dashboard)/layout.tsx
@@ -118,7 +118,7 @@ export default function DashboardLayout({
       </header>
 
       {/* Sidebar */}
-      <aside className="fixed left-0 top-0 h-full w-72 bg-surface-container-lowest flex flex-col py-6 border-r border-surface-container z-40">
+      <aside className="fixed left-0 top-0 z-[60] h-full w-72 bg-surface-container-lowest flex flex-col py-6 border-r border-surface-container">
         {/* Sidebar Header */}
         <div className="mt-12 px-6 mb-6">
           <div className="flex items-center gap-3">
diff --git a/src/app/(dashboard)/products/[productId]/detail/page.tsx b/src/app/(dashboard)/products/[productId]/detail/page.tsx
index b69c004..ab79d8d 100644
--- a/src/app/(dashboard)/products/[productId]/detail/page.tsx
+++ b/src/app/(dashboard)/products/[productId]/detail/page.tsx
@@ -304,7 +304,7 @@ function ProductDetailPageInner() {
   const features = Array.isArray(product.productFeatures) ? product.productFeatures.filter(Boolean) : [];
   const productInfos = Array.isArray(product.productInformations) ? product.productInformations.filter((i: { paramName: string; paramValue: string }) => i.paramName && i.paramValue) : [];
   const categoryInfos = Array.isArray(product.categoryInformations) ? product.categoryInformations.filter((i: { paramName: string; paramValue: string }) => i.paramName && i.paramValue) : [];
-  const allImages: Array<{ id?: string; url: string }> = [
+  const rawImages: Array<{ id?: string; url: string }> = [
     ...(product.imageId || product.image
       ? [{ id: product.imageId, url: resolveImageUrl(product.imageId, product.image) }]
       : []),
@@ -321,6 +321,13 @@ function ProductDetailPageInner() {
           .filter((img) => isNonEmptyString(img.url))
       : []),
   ];
+  const seenImages = new Set<string>();
+  const allImages = rawImages.filter((img) => {
+    const key = img.id || img.url;
+    if (!key || seenImages.has(key)) return false;
+    seenImages.add(key);
+    return true;
+  });
   const isReviewProduct = isReview || product.state === "REVIEW";
 
   return (
diff --git a/src/app/(dashboard)/products/[productId]/edit/page.tsx b/src/app/(dashboard)/products/[productId]/edit/page.tsx
index 550da5a..5b875a1 100644
--- a/src/app/(dashboard)/products/[productId]/edit/page.tsx
+++ b/src/app/(dashboard)/products/[productId]/edit/page.tsx
@@ -1337,6 +1337,14 @@ function EditProductPageInner() {
   function buildPayload(state?: "DRAFT" | "REVIEW") {
     if (!form) return null;
     const resolvedState = state ?? "DRAFT";
+    const productImageIds = form.productImages.filter(Boolean);
+    const hasMainImageInProductImages = Boolean(
+      form.imageId && productImageIds.includes(form.imageId)
+    );
+    const productImagesWithMain = [
+      ...(hasMainImageInProductImages ? [] : [form.imageId]),
+      ...productImageIds,
+    ].filter(Boolean);
     const base = {
       subCategory: form.subCategoryId ? { id: form.subCategoryId } : undefined,
       name: form.name,
@@ -1345,9 +1353,9 @@ function EditProductPageInner() {
       preOrderDay: form.isPreOrder ? toNum(form.preOrderDay) : null,
       isNew: form.isNew,
       isEligibleToExport: form.isEligibleToExport,
-      imageId: form.imageId || undefined,
+      imageId: form.imageId || null,
       productFiles: form.productFiles.map((file) => file.id).filter(Boolean),
-      productImages: form.productImages.filter(Boolean).map((imageId, i) => ({ imageId, sequence: i + 1 })),
+      productImages: productImagesWithMain.map((imageId, i) => ({ imageId, sequence: i + 1 })),
       productKeyWords: form.keywords.filter(Boolean).slice(0, 3),
       productFeatures: form.features.filter(Boolean).slice(0, 5),
       productModels: form.models.map((m) => ({
@@ -1529,6 +1537,11 @@ function EditProductPageInner() {
   }
 
   // ── Render ──
+  const visibleGalleryImages = form.productImages
+    .map((imageId, index) => ({ imageId, index }))
+    .filter((item) => !item.imageId || item.imageId !== form.imageId);
+  const visibleImageSlotCount = 1 + visibleGalleryImages.length;
+
   return (
     <div className="w-full px-6 md:px-10 py-8 pb-36 space-y-8">
       {/* Page header */}
@@ -1729,30 +1742,43 @@ function EditProductPageInner() {
         <div className="xl:col-span-5 bg-surface-container-lowest rounded-2xl border border-outline-variant/10 shadow-sm p-8 space-y-4">
           <div className="flex items-center justify-between">
             <label className="text-[11px] font-black uppercase tracking-[0.18em] text-outline block">{e.visualIdentity}</label>
-            <span className="text-[10px] font-bold text-outline">{1 + form.productImages.length} / {MAX_IMAGES}</span>
+            <span className="text-[10px] font-bold text-outline">{visibleImageSlotCount} / {MAX_IMAGES}</span>
           </div>
           <div className="space-y-2">
             <ImageSlotUpload
               fileId={form.imageId}
               label={e.mainImage}
-              onUploaded={(id) => update({ imageId: id })}
-              onRemove={() => update({ imageId: "" })}
+              onUploaded={(id) => {
+                const previousMainImageId = form.imageId;
+                const updatedProductImages = previousMainImageId
+                  ? form.productImages.map((imageId) =>
+                      imageId === previousMainImageId ? id : imageId
+                    )
+                  : form.productImages;
+                update({ imageId: id, productImages: updatedProductImages });
+              }}
+              onRemove={() =>
+                update({
+                  imageId: "",
+                  productImages: form.productImages.filter((imageId) => imageId !== form.imageId),
+                })
+              }
             />
-            {form.productImages.map((imgId, i) => (
+            {visibleGalleryImages.map((item, visibleIndex) => (
               <ImageSlotUpload
-                key={i}
-                fileId={imgId}
-                label={`${e.gallery} ${i + 1}`}
+                key={item.index}
+                fileId={item.imageId}
+                label={`${e.gallery} ${visibleIndex + 1}`}
                 onUploaded={(id) => {
                   const updated = [...form.productImages];
-                  updated[i] = id;
+                  updated[item.index] = id;
                   update({ productImages: updated });
                 }}
-                onRemove={() => update({ productImages: form.productImages.filter((_, xi) => xi !== i) })}
+                onRemove={() => update({ productImages: form.productImages.filter((_, xi) => xi !== item.index) })}
               />
             ))}
           </div>
-          {1 + form.productImages.length < MAX_IMAGES && (
+          {visibleImageSlotCount < MAX_IMAGES && (
             <button type="button"
               onClick={() => update({ productImages: [...form.productImages, ""] })}
               className="w-full flex items-center justify-center gap-2 py-3 rounded-xl border-2 border-dashed border-outline-variant/40 text-on-surface-variant hover:border-primary hover:text-primary transition-colors text-sm font-bold">
diff --git a/src/app/(dashboard)/products/page.tsx b/src/app/(dashboard)/products/page.tsx
index c496105..ff8eb8b 100644
--- a/src/app/(dashboard)/products/page.tsx
+++ b/src/app/(dashboard)/products/page.tsx
@@ -794,6 +794,14 @@ function ProductsPageInner() {
 
   useEffect(() => {
     setOpenActionMenuId(null);
+    setActionMenuPosition(null);
+    setDeleteTarget(null);
+    setUnpublishTarget(null);
+    setStockPriceTarget(null);
+    setDeleting(false);
+    setUnpublishing(false);
+    setPublishingId(null);
+    setRestoringId(null);
   }, [tab, page]);
 
   useEffect(() => {
@@ -966,11 +974,18 @@ function ProductsPageInner() {
 
       const query = searchParams.toString();
       const url = `/api/products/${deleteTarget.id}${query ? `?${query}` : ""}`;
-      await fetch(url, { method: "DELETE", headers: { "x-auth-token": getToken() } });
+      const res = await fetch(url, { method: "DELETE", headers: { "x-auth-token": getToken() } });
+      const result = await res.json().catch(() => ({}));
+
+      if (!res.ok) {
+        throw new Error(result?.responseDesc || p.deleteDialog.errorGeneric);
+      }
+
       setDeleteTarget(null);
       window.location.reload();
-    } catch {
-      alert(p.deleteDialog.errorGeneric);
+    } catch (err) {
+      alert(err instanceof Error ? err.message : p.deleteDialog.errorGeneric);
+      setDeleteTarget(null);
     } finally {
       setDeleting(false);
     }
@@ -994,6 +1009,7 @@ function ProductsPageInner() {
       window.location.reload();
     } catch (err) {
       alert(err instanceof Error ? err.message : p.unpublishDialog.errorGeneric);
+      setUnpublishTarget(null);
     } finally {
       setUnpublishing(false);
     }
@@ -1104,17 +1120,9 @@ function ProductsPageInner() {
           : current
       );
     } catch (err) {
+      alert(err instanceof Error ? err.message : p.stockPriceDialog.loadError);
       setStockPriceTarget((current) =>
-        current && current.product.id === product.id
-          ? {
-              ...current,
-              loading: false,
-              error:
-                err instanceof Error
-                  ? err.message
-                  : p.stockPriceDialog.loadError,
-            }
-          : current
+        current && current.product.id === product.id ? null : current
       );
     }
   }
diff --git a/src/components/product-submenu-nav.tsx b/src/components/product-submenu-nav.tsx
index b43119c..b4cdcff 100644
--- a/src/components/product-submenu-nav.tsx
+++ b/src/components/product-submenu-nav.tsx
@@ -1,10 +1,11 @@
 "use client";
 
-import { usePathname, useRouter, useSearchParams } from "next/navigation";
+import Link from "next/link";
+import { usePathname, useSearchParams } from "next/navigation";
 import { Suspense } from "react";
 
 const productSubmenu = [
-  { label: "All Product", href: "/products" },
+  { label: "All Product", href: "/products?tab=all" },
   { label: "Draft", href: "/products?tab=draft" },
   { label: "In Review", href: "/products?tab=in-review" },
   { label: "International Market", href: "/products?tab=international-market" },
@@ -16,7 +17,6 @@ const productSubmenu = [
 
 function ProductSubmenuNavInner() {
   const pathname = usePathname();
-  const router = useRouter();
   const searchParams = useSearchParams();
   const rawTab = searchParams.get("tab") ?? "";
   const currentTab = rawTab === "all" ? "" : rawTab;
@@ -29,16 +29,15 @@ function ProductSubmenuNavInner() {
         const submenuTab = new URLSearchParams(
           submenu.href.split("?")[1] || ""
         ).get("tab") ?? "";
-        const isAllProduct = submenu.href === "/products";
+        const isAllProduct = submenuTab === "all";
         const isSubmenuActive =
           pathname === "/products" &&
           (isAllProduct ? currentTab === "" : submenuTab === currentTab);
 
         return (
-          <button
+          <Link
             key={submenu.href}
-            type="button"
-            onClick={() => router.push(submenu.href)}
+            href={submenu.href}
             className={`relative z-10 flex w-full items-center py-2 pl-3 text-left text-sm font-semibold transition-all rounded-r-xl pointer-events-auto ${
               isSubmenuActive
                 ? "bg-white text-primary border-l-4 border-primary shadow-sm rounded-l-none"
@@ -46,7 +45,7 @@ function ProductSubmenuNavInner() {
             }`}
           >
             {submenu.label}
-          </button>
+          </Link>
         );
       })}
     </div>
diff --git a/src/components/product-variant-showcase.tsx b/src/components/product-variant-showcase.tsx
index 1bfc13c..8fe123b 100644
--- a/src/components/product-variant-showcase.tsx
+++ b/src/components/product-variant-showcase.tsx
@@ -96,16 +96,25 @@ export function ProductVariantShowcase({
   const productImages = getAllProductImageRefs(product);
   const [selectedModelIndex, setSelectedModelIndex] = useState(0);
   const [selectedMeasurementIndex, setSelectedMeasurementIndex] = useState(0);
+  const [selectedImageIndex, setSelectedImageIndex] = useState(0);
 
   const selectedModel = models[selectedModelIndex] || null;
   const measurements = selectedModel ? getModelMeasurements(selectedModel) : [];
   const hasMeasurements = selectedModel ? modelHasMeasurements(selectedModel) : false;
   const selectedMeasurement = hasMeasurements ? measurements[selectedMeasurementIndex] || measurements[0] || null : null;
+  const selectedProductImage =
+    productImages.length > 0
+      ? productImages[Math.min(selectedImageIndex, productImages.length - 1)]
+      : null;
   const selectedImageId =
+    selectedProductImage?.id ||
     (selectedModel?.imageId as string | undefined) ||
     productImages[0]?.id ||
     null;
-  const selectedImageUrl = imgUrl(selectedImageId, selectedModel?.image || productImages[0]?.url);
+  const selectedImageUrl = imgUrl(
+    selectedImageId,
+    selectedProductImage?.url || selectedModel?.image || productImages[0]?.url
+  );
 
   const selectedPrice = selectedMeasurement
     ? formatMoney(selectedMeasurement.price, selectedMeasurement.currency || selectedModel?.currency)
@@ -185,15 +194,23 @@ export function ProductVariantShowcase({
                 )}
               </div>
               {productImages.length > 1 ? (
-                <div className="grid grid-cols-4 gap-2">
-                  {productImages.slice(0, 4).map((imageRef, index) => {
+                <div className="flex gap-2 overflow-x-auto pb-1">
+                  {productImages.map((imageRef, index) => {
                     const image = imgUrl(imageRef.id, imageRef.url);
                     if (!image) return null;
+                    const active = index === Math.min(selectedImageIndex, productImages.length - 1);
                     return (
-                      <div key={`${imageRef.id || imageRef.url}-${index}`} className="aspect-square overflow-hidden rounded-xl border border-surface-container bg-surface-container-low">
+                      <button
+                        key={`${imageRef.id || imageRef.url}-${index}`}
+                        type="button"
+                        onClick={() => setSelectedImageIndex(index)}
+                        className={`h-20 w-20 flex-shrink-0 overflow-hidden rounded-xl border bg-surface-container-low transition-all ${
+                          active ? "border-primary ring-2 ring-primary/20" : "border-surface-container hover:border-primary/40"
+                        }`}
+                      >
                         {/* eslint-disable-next-line @next/next/no-img-element */}
                         <img src={image} alt={`gallery-${index + 1}`} className="h-full w-full object-cover" />
-                      </div>
+                      </button>
                     );
                   })}
                 </div>
diff --git a/src/lib/product-variants.ts b/src/lib/product-variants.ts
index dd29e2d..3034dc2 100644
--- a/src/lib/product-variants.ts
+++ b/src/lib/product-variants.ts
@@ -118,10 +118,15 @@ export function getSortedProductImages(product: VariantProductLike) {
 }
 
 export function getAllProductImageIds(product: VariantProductLike) {
+  const seen = new Set<string>();
   return [
     ...(product.imageId ? [product.imageId] : []),
     ...getSortedProductImages(product),
-  ];
+  ].filter((imageId) => {
+    if (seen.has(imageId)) return false;
+    seen.add(imageId);
+    return true;
+  });
 }
 
 export function getSortedProductImageRefs(product: VariantProductLike) {
@@ -136,10 +141,17 @@ export function getSortedProductImageRefs(product: VariantProductLike) {
 }
 
 export function getAllProductImageRefs(product: VariantProductLike) {
+  const seen = new Set<string>();
   return [
     ...(product.imageId || product.image ? [{ id: product.imageId || null, url: product.image || null }] : []),
     ...getSortedProductImageRefs(product),
-  ];
+  ].filter((item) => {
+    const key = item.id || item.url;
+    if (!key) return false;
+    if (seen.has(key)) return false;
+    seen.add(key);
+    return true;
+  });
 }
 
 export function getModelMeasurements(model: VariantModelLike) {