feat: locale-based generation, describe field for batch cooking; fix bulk-bar width and sourceUrl not saving

- AI recipe generation always used the app's own locale rather than a
  separate language picker — removed the picker, generation and the
  saved recipe's language now both follow useLocale() directly.
- Bulk-select action bar had an ungated max-w-md that capped it at 448px
  even past the sm: breakpoint where sm:w-auto was supposed to let it
  grow to content — added sm:max-w-none so desktop never scrolls.
- Batch-cooking generation had no free-text "describe" field like the
  standard recipe generator does — added one (BatchCookFields, both the
  standalone dialog and the AI dialog's batch tab), threaded through the
  API route and generateBatchCook's prompt as additional guidance.
- Recipes imported from a URL never actually got their sourceUrl
  persisted — CreateRecipeSchema didn't declare the field, so Zod
  silently stripped it before it ever reached the insert. The detail
  page's "Source: <hostname>" link already existed but was dead code
  for every real import until now.

Verified all 4 live: generate dialog has no language selector, batch
tab has a working describe textarea, bulk-select bar renders at full
content width with zero horizontal overflow on desktop, and a recipe
created with sourceUrl now round-trips and renders its source link.

apps/web/components/recipe/batch-cook-fields.tsx

@@ -5,6 +5,7 @@ import { Minus, Plus } from "lucide-react";
 import { Button } from "@/components/ui/button";
 import { Label } from "@/components/ui/label";
 import { Input } from "@/components/ui/input";
+import { Textarea } from "@/components/ui/textarea";
 import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from "@/components/ui/select";
 
 function Counter({
@@ -37,6 +38,7 @@ export type BatchCookFieldsState = {
   servings: number;
   difficulty: "" | "easy" | "medium" | "hard";
   dietaryPrefs: string;
+  description: string;
 };
 
 export function BatchCookFields({
@@ -54,6 +56,17 @@ export function BatchCookFields({
 
   return (
     <div className="space-y-4">
+      <div className="space-y-2">
+        <Label htmlFor="batch-description">{t("describe")}</Label>
+        <Textarea
+          id="batch-description"
+          value={state.description}
+          onChange={(e) => onChange({ ...state, description: e.target.value })}
+          placeholder={t("describePlaceholder")}
+          rows={3}
+          disabled={disabled}
+        />
+      </div>
       <div className="flex items-center justify-between">
         <Label>{t("dinners")}</Label>
         <Counter value={state.dinners} onChange={(v) => onChange({ ...state, dinners: v })} disabled={disabled} />