refactor: remove duplicate header labels on backlog page

Both the product H1 + description in the page header and the
"Product Backlog" panel-title in the PBI panel duplicated info
already visible in the NavBar. Removed both, keeping the right-aligned
action bars (activate/sprint/settings, plus filters/+PBI) intact.

PanelNavBar component is unchanged — Stories and Taken panels keep
their titles.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

app/(app)/products/[id]/page.tsx

@@ -92,14 +92,8 @@ export default async function ProductBacklogPage({ params, searchParams }: Props
 
   return (
     <div className="flex flex-col h-full">
-      {/* Product header */}
-      <div className="px-4 py-3 border-b border-border bg-surface-container-low shrink-0 flex items-center justify-between">
-        <div>
-          <h1 className="font-medium text-foreground">{product.name}</h1>
-          {product.description && (
-            <p className="text-xs text-muted-foreground mt-0.5">{product.description}</p>
-          )}
-        </div>
+      {/* Product header — actions only; product-naam zit al in NavBar */}
+      <div className="px-4 py-3 border-b border-border bg-surface-container-low shrink-0 flex items-center justify-end">
         <div className="flex items-center gap-3">
           {user?.active_product_id !== id && (
             <ActivateProductButton productId={id} isDemo={isDemo} redirectTo={`/products/${id}`} />

components/backlog/pbi-list.tsx

@@ -24,7 +24,6 @@ import { toast } from 'sonner'
 import { Button } from '@/components/ui/button'
 import { Badge } from '@/components/ui/badge'
 import { Popover, PopoverContent, PopoverTrigger } from '@/components/ui/popover'
-import { PanelNavBar } from '@/components/shared/panel-nav-bar'
 import { useSelectionStore } from '@/stores/selection-store'
 import { usePlannerStore } from '@/stores/planner-store'
 import { useBacklogStore } from '@/stores/backlog-store'
@@ -330,10 +329,7 @@ export function PbiList({ productId, isDemo }: PbiListProps) {
 
   return (
     <div className="flex flex-col h-full">
-      <PanelNavBar
-        title="Product Backlog"
-        actions={
-          <>
+      <div className="flex items-center justify-end gap-2 px-4 py-2 border-b border-border bg-surface-container-low shrink-0">
         {filterPriority !== 'all' && (
           <button
             onClick={() => setFilterPriority('all')}
@@ -413,9 +409,7 @@ export function PbiList({ productId, isDemo }: PbiListProps) {
             + PBI
           </Button>
         </DemoTooltip>
-          </>
-        }
-      />
+      </div>
 
       <div className="flex-1 overflow-y-auto">
         {pbis.length === 0 ? (