fix: storefront live search relative URLs + auth error messages + TPV clock

- Storefront: use relative URLs in api.ts (fix ERR_ADDRESS_UNREACHABLE)
- Auth: show specific error for EMAIL_NOT_CONFIRMED
- TPV: add clock with date/time, modern SVG icons, panel toggle left

project/storefront/src/components/add-to-cart.tsx

@@ -41,7 +41,7 @@ export function AddToCart({ productId, productName, unitPriceCents, imageUrl }:
   const [added, setAdded] = useState<boolean>(false);
 
   useEffect(() => {
-    fetch(`/api/inventory/${encodeURIComponent(productId)}/availability`)
+    fetch(`/api/inventory/product/${encodeURIComponent(productId)}/availability`)
       .then(async (r) => (r.ok ? await r.json() : { availableQuantity: 0 }))
       .then((j) => setStock(j.availableQuantity ?? 0))
       .catch(() => setStock(0));

project/storefront/src/lib/api.ts

@@ -77,14 +77,10 @@ export interface SearchProductsInput {
   offset?: number;
 }
 
-const DEFAULT_API_BASE_URL = 'http://localhost:3000';
-
+// Use env var if set, otherwise use relative URL (works for SSR and client-side via same-origin)
 function apiBaseUrl(): string {
-  return (
-    process.env.API_BASE_URL ??
-    process.env.NEXT_PUBLIC_API_BASE_URL ??
-    DEFAULT_API_BASE_URL
-  ).replace(/\/$/, '');
+  const base = process.env.API_BASE_URL ?? process.env.NEXT_PUBLIC_API_BASE_URL ?? '';
+  return base.replace(/\/$/, '');
 }
 
 function toQueryString(input: SearchProductsInput): string {