feat: add batch-cooking sessions (single "mega recipe" with dish sections)

New AI-generated batch-cooking flow: pick N dinners/lunches + servings,
get one unified recipe covering a full prep session — merged shopping
list, steps tagged per-dish (a step can advance several dishes at once,
e.g. a shared oven bake), and per-dish storage (fridge/freezer) + exact
day-of reheat/finishing instructions.

Schema: recipes.isBatchCook, recipeSteps.appliesTo (dish names), new
recipeBatchDishes table. Batch recipes are excluded from the normal
/recipes list and live under their own /batch-cooking section.

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

apps/web/components/recipe/recipes-header.tsx

@@ -3,7 +3,7 @@
 import { useState, useTransition } from "react";
 import Link from "next/link";
 import { useRouter, usePathname } from "next/navigation";
-import { PlusCircle, Sparkles, Link2, Search, X, SlidersHorizontal, ArrowUpDown } from "lucide-react";
+import { PlusCircle, Sparkles, Link2, Search, X, SlidersHorizontal, ArrowUpDown, ChefHat } from "lucide-react";
 import { useTranslations } from "next-intl";
 import { Button, buttonVariants } from "@/components/ui/button";
 import { Input } from "@/components/ui/input";
@@ -122,6 +122,10 @@ export function RecipesHeader({
             </p>
           </div>
           <div className="flex flex-wrap items-center gap-2">
+            <Link href="/batch-cooking" className={cn(buttonVariants({ variant: "outline", size: "sm" }), "gap-1.5")}>
+              <ChefHat className="h-4 w-4" />
+              {t("batchCooking")}
+            </Link>
             <Button variant="ghost" size="sm" onClick={() => setUrlOpen(true)}>
               <Link2 className="h-4 w-4" />
               {t("importUrl")}