feat: show active product name in navbar, links to product page

Sub-layout sets product in Zustand store; NavBar reads it.
getAccessibleProduct wrapped with React cache to avoid double DB call.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

components/shared/nav-bar.tsx

@@ -7,6 +7,7 @@ import { Button } from '@/components/ui/button'
 import { Badge } from '@/components/ui/badge'
 import { AppIcon } from '@/components/shared/app-icon'
 import { cn } from '@/lib/utils'
+import { useProductStore } from '@/stores/product-store'
 
 const ROLE_LABELS: Record<string, string> = {
   PRODUCT_OWNER: 'PO',
@@ -21,6 +22,7 @@ interface NavBarProps {
 
 export function NavBar({ isDemo, roles }: NavBarProps) {
   const pathname = usePathname()
+  const currentProduct = useProductStore(s => s.currentProduct)
 
   const productMatch = pathname.match(/^\/products\/([^/]+)/)
   const productId = productMatch ? productMatch[1] : null
@@ -81,6 +83,17 @@ export function NavBar({ isDemo, roles }: NavBarProps) {
             {roles.map(r => ROLE_LABELS[r]).filter(Boolean).join(' · ')}
           </span>
         )}
+        {currentProduct && (
+          <Link
+            href={`/products/${currentProduct.id}`}
+            className="text-xs text-muted-foreground hover:text-foreground transition-colors px-2 truncate max-w-[160px]"
+            title={currentProduct.name}
+          >
+            {currentProduct.name.length > 20
+              ? currentProduct.name.slice(0, 20) + '…'
+              : currentProduct.name}
+          </Link>
+        )}
         <Link
           href="/settings"
           className={cn(

components/shared/set-current-product.tsx

@@ -0,0 +1,15 @@
+'use client'
+
+import { useEffect } from 'react'
+import { useProductStore } from '@/stores/product-store'
+
+export function SetCurrentProduct({ id, name }: { id: string; name: string }) {
+  const { setCurrentProduct, clearCurrentProduct } = useProductStore()
+
+  useEffect(() => {
+    setCurrentProduct(id, name)
+    return () => clearCurrentProduct()
+  }, [id, name, setCurrentProduct, clearCurrentProduct])
+
+  return null
+}