fix(i18n): translate remaining recipe card/detail strings, localize AI responses

Recipe cards, the recipe detail page, and meal planner still rendered raw
"{n} servings"/"{n}m cook"/"{n} srv" text and untranslated difficulty labels
outside the earlier i18n pass. Also wires the user's locale into AI features
that previously always answered in English regardless of app language:
recipe chat, ingredient substitution, recipe ideas, and generate-from-idea.
The recipe-language picker in the AI generate dialog now defaults to the
user's locale instead of always defaulting to English.

apps/web/components/search/explore-page-content.tsx

@@ -43,8 +43,12 @@ type RecipeIdea = {
 };
 
 function RecipeCard({ recipe }: { recipe: ExploreRecipeResult | SearchRecipeResult }) {
+  const t = useTranslations("recipe");
   const totalMins = (recipe.prepMins ?? 0) + (recipe.cookMins ?? 0);
   const description = "description" in recipe ? recipe.description : null;
+  const difficultyLabel = recipe.difficulty === "easy" || recipe.difficulty === "medium" || recipe.difficulty === "hard"
+    ? t(`difficulty.${recipe.difficulty}`)
+    : recipe.difficulty;
   return (
     <Link
       href={`/recipes/${recipe.id}`}
@@ -59,7 +63,7 @@ function RecipeCard({ recipe }: { recipe: ExploreRecipeResult | SearchRecipeResu
             variant="secondary"
             className={`shrink-0 capitalize text-xs ${DIFFICULTY_COLORS[recipe.difficulty] ?? ""}`}
           >
-            {recipe.difficulty}
+            {difficultyLabel}
           </Badge>
         )}
       </div>
@@ -70,7 +74,7 @@ function RecipeCard({ recipe }: { recipe: ExploreRecipeResult | SearchRecipeResu
         {totalMins > 0 && (
           <span className="flex items-center gap-1">
             <Clock className="h-3.5 w-3.5" />
-            {totalMins}m
+            {t("total", { mins: totalMins })}
           </span>
         )}
         {recipe.authorName && (
@@ -103,6 +107,7 @@ export function ExplorePageContent({ trending, recent, initialQuery }: Props) {
   const searchParams = useSearchParams();
   const t = useTranslations("explore");
   const tCommon = useTranslations("common");
+  const tRecipe = useTranslations("recipe");
 
   const [inputValue, setInputValue] = useState(initialQuery);
   const [query, setQuery] = useState(initialQuery);
@@ -388,7 +393,7 @@ export function ExplorePageContent({ trending, recent, initialQuery }: Props) {
                         variant="secondary"
                         className={`shrink-0 capitalize text-xs ${DIFFICULTY_COLORS[idea.difficulty] ?? ""}`}
                       >
-                        {idea.difficulty}
+                        {tRecipe(`difficulty.${idea.difficulty}`)}
                       </Badge>
                     </div>
                     <p className="text-xs text-muted-foreground line-clamp-2 flex-1">{idea.description}</p>
@@ -398,7 +403,7 @@ export function ExplorePageContent({ trending, recent, initialQuery }: Props) {
                       ))}
                       {idea.totalMins && (
                         <Badge variant="outline" className="text-xs flex items-center gap-1">
-                          <Clock className="h-3 w-3" />{idea.totalMins}m
+                          <Clock className="h-3 w-3" />{tRecipe("total", { mins: idea.totalMins })}
                         </Badge>
                       )}
                     </div>