feat: copy/export as Markdown wherever print exists

Added a shared ExportMarkdownButton (copy to clipboard / download .md)
next to every existing print button: recipe, shopping list,
collection, meal plan, pantry. Each surface gets a small serializer in
lib/markdown/ built from data already in scope at that page — no new
queries except pantry, where items now thread through as a prop to
PantryPageHeader instead of being fetched only for PantryManager.

Also fixes an unrelated bug hit while verifying the collection export:
RecipeCard called the client-only useTranslations() hook without
"use client", so it rendered fine everywhere it happened to run inside
an already-client tree but 500'd — "Couldn't find next-intl config
file" — when Next tried to run it as a Server Component, which only
happens on the collection detail page (its only caller). Collections
with recipes in them were completely broken.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

apps/web/app/(app)/shopping-lists/[id]/page.tsx

@@ -11,6 +11,8 @@ import { GroceryExportButton } from "@/components/shopping-lists/grocery-export-
 import { buttonVariants } from "@/components/ui/button";
 import { cn } from "@/lib/utils";
 import { getShoppingListAccess, canWriteShoppingList } from "@/lib/shopping-list-access";
+import { ExportMarkdownButton } from "@/components/shared/export-markdown-button";
+import { shoppingListToMarkdown } from "@/lib/markdown/shopping-list";
 import { getMessages, formatMessage } from "@/lib/i18n/server";
 
 type Params = { params: Promise<{ id: string }> };
@@ -52,6 +54,10 @@ export default async function ShoppingListPage({ params }: Params) {
             <Printer className="h-4 w-4" />
             {m.common.print}
           </Link>
+          <ExportMarkdownButton
+            markdown={shoppingListToMarkdown({ name: list.name, items: list.items })}
+            filename={list.name}
+          />
         </div>
       </div>
       <ShoppingListView