feat(admin): issue #145 — delete-blocked hint + Deactivate/Edit alternative

- categories dialog: red hint with count + Deactivate button when products>0
- locations dialog: red hint + Deactivate button when categories/products>0
- catalog dialog: deleteError shown on 400/409; Deactivate for category/subcategory/location, Edit for product
- Deactivate calls existing PATCH toggle, closes dialog, reloads
- tsc clean

admin-next/src/components/catalog/catalog-page.tsx

@@ -211,6 +211,7 @@ export function CatalogPage() {
     id: number;
     name: string;
   } | null>(null);
+  const [deleteError, setDeleteError] = useState<string | null>(null);
 
   // Inline rename state
   const [renamingId, setRenamingId] = useState<string | null>(null);
@@ -353,14 +354,38 @@ export function CatalogPage() {
       const res = await fetch(`/api/${typePath}/${deleteTarget.id}`, { method: "DELETE" });
       if (!res.ok) {
         const data = await res.json();
-        throw new Error(data.error || "Failed to delete");
+        const msg = data.error || "Failed to delete";
+        setDeleteError(msg);
+        toast.error(msg);
+        return;
       }
       toast.success(`${deleteTarget.type} deleted`);
       setDeleteTarget(null);
+      setDeleteError(null);
       fetchTree();
       fetchProducts();
     } catch (e) {
-      toast.error(e instanceof Error ? e.message : "Failed to delete");
+      const msg = e instanceof Error ? e.message : "Failed to delete";
+      setDeleteError(msg);
+      toast.error(msg);
+    }
+  };
+
+  const handleDeactivateFromCatalog = () => {
+    if (!deleteTarget) return;
+    handleToggleActive(deleteTarget.type, deleteTarget.id);
+    setDeleteTarget(null);
+    setDeleteError(null);
+  };
+
+  const handleEditFromCatalog = () => {
+    if (!deleteTarget || deleteTarget.type !== "product") return;
+    // Find the product in the current products list
+    const product = products.find((p) => p.id === deleteTarget.id);
+    setDeleteTarget(null);
+    setDeleteError(null);
+    if (product) {
+      openProductModal(product);
     }
   };
 
@@ -1488,17 +1513,32 @@ export function CatalogPage() {
       </Dialog>
 
       {/* ─── Delete Confirmation ─── */}
-      <AlertDialog open={!!deleteTarget} onOpenChange={(open) => !open && setDeleteTarget(null)}>
+      <AlertDialog open={!!deleteTarget} onOpenChange={(open) => { if (!open) { setDeleteTarget(null); setDeleteError(null); } }}>
         <AlertDialogContent>
           <AlertDialogHeader>
             <AlertDialogTitle>Delete {deleteTarget?.type}?</AlertDialogTitle>
             <AlertDialogDescription>
               Are you sure you want to delete &quot;{deleteTarget?.name}&quot;? This action cannot be
               undone.
+              {deleteError && (
+                <span className="block mt-2 text-red-600 font-medium">
+                  {deleteError}
+                </span>
+              )}
             </AlertDialogDescription>
           </AlertDialogHeader>
           <AlertDialogFooter>
             <AlertDialogCancel>Cancel</AlertDialogCancel>
+            {deleteError && deleteTarget && deleteTarget.type !== "product" && (
+              <Button variant="outline" onClick={handleDeactivateFromCatalog}>
+                🔕 Deactivate
+              </Button>
+            )}
+            {deleteError && deleteTarget && deleteTarget.type === "product" && (
+              <Button variant="outline" onClick={handleEditFromCatalog}>
+                ✏️ Edit
+              </Button>
+            )}
             <AlertDialogAction
               onClick={handleDelete}
               className="bg-destructive text-destructive-foreground hover:bg-destructive/90"

admin-next/src/components/categories/categories-page.tsx

@@ -242,6 +242,12 @@ export function CategoriesPage() {
     }
   };
 
+  const handleDeactivate = () => {
+    if (!deleteTarget) return;
+    handleToggle(deleteTarget);
+    setDeleteTarget(null);
+  };
+
   // Group locations by country > city > district
   const groupedLocations = locations.reduce<Record<string, Record<string, Record<string, LocationItem>>>>(
     (acc, loc) => {
@@ -469,13 +475,18 @@ export function CategoriesPage() {
               Are you sure you want to delete &quot;{deleteTarget?.name}&quot;? This action cannot be undone.
               {deleteTarget && deleteTarget._count.products > 0 && (
                 <span className="block mt-2 text-red-600 font-medium">
-                  This category has {deleteTarget._count.products} product(s) and cannot be deleted.
+                  This category has {deleteTarget._count.products} product(s) and cannot be deleted. You can deactivate it instead.
                 </span>
               )}
             </AlertDialogDescription>
           </AlertDialogHeader>
           <AlertDialogFooter>
             <AlertDialogCancel>Cancel</AlertDialogCancel>
+            {deleteTarget && deleteTarget._count.products > 0 && (
+              <Button variant="outline" onClick={handleDeactivate}>
+                🔕 Deactivate
+              </Button>
+            )}
             <AlertDialogAction
               onClick={handleDelete}
               disabled={deleting || (deleteTarget ? deleteTarget._count.products > 0 : true)}

admin-next/src/components/locations/locations-page.tsx

@@ -201,6 +201,12 @@ export function LocationsPage() {
     }
   };
 
+  const handleDeactivate = () => {
+    if (!deleteTarget) return;
+    handleToggle(deleteTarget);
+    setDeleteTarget(null);
+  };
+
   return (
     <div className="page-enter p-4 md:p-6 space-y-4">
       <div className="flex flex-col sm:flex-row sm:items-center sm:justify-between gap-4">
@@ -344,13 +350,18 @@ export function LocationsPage() {
               {deleteTarget && (deleteTarget._count.categories > 0 || deleteTarget._count.products > 0) && (
                 <span className="block mt-2 text-red-600 font-medium">
                   This location has {deleteTarget._count.categories} categor{deleteTarget._count.categories === 1 ? "y" : "ies"}
-                  and {deleteTarget._count.products} product(s) and cannot be deleted.
+                  {" "}and {deleteTarget._count.products} product(s) and cannot be deleted. You can deactivate it instead.
                 </span>
               )}
             </AlertDialogDescription>
           </AlertDialogHeader>
           <AlertDialogFooter>
             <AlertDialogCancel>Cancel</AlertDialogCancel>
+            {deleteTarget && (deleteTarget._count.categories > 0 || deleteTarget._count.products > 0) && (
+              <Button variant="outline" onClick={handleDeactivate}>
+                🔕 Deactivate
+              </Button>
+            )}
             <AlertDialogAction
               onClick={handleDelete}
               disabled={deleting || (deleteTarget ? (deleteTarget._count.categories > 0 || deleteTarget._count.products > 0) : true)}