refactor: merge api/recipes and api/rezepte into unified recipeLang route

Consolidate duplicate recipe API routes into a single
api/[recipeLang=recipeLang]/ structure. Both /api/recipes/ and
/api/rezepte/ URLs continue to work via the param matcher. Shared
read endpoints now serve both languages with caching for both.

Also: remove dead code (5 unused components, cookie.js) and the
redundant cron-execute recurring payment route.

src/routes/[recipeLang=recipeLang]/+page.server.ts

@@ -2,8 +2,7 @@ import type { PageServerLoad } from "./$types";
 import { getUserFavorites, addFavoriteStatusToRecipes } from "$lib/server/favorites";
 
 export const load: PageServerLoad = async ({ fetch, locals, params }) => {
-    const isEnglish = params.recipeLang === 'recipes';
-    const apiBase = isEnglish ? '/api/recipes' : '/api/rezepte';
+    const apiBase = `/api/${params.recipeLang}`;
 
     let current_month = new Date().getMonth() + 1
     const res_season = await fetch(`${apiBase}/items/in_season/` + current_month);