refactor: clean up recipe routes and reduce bundle size

- Eliminate duplicate API fetch in recipe page by passing item from
  server load to universal load instead of fetching twice
- Replace cheerio with simple regex in stripHtmlTags, removing ~200KB
  dependency
- Refactor multiplier buttons in IngredientsPage to use loop instead
  of 5 repeated form elements
- Move /rezepte/untranslated to /[recipeLang]/admin/untranslated and
  delete legacy /rezepte/ layout files

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

@@ -0,0 +1,45 @@
+import type { PageServerLoad } from "./$types";
+import { redirect, error } from '@sveltejs/kit';
+
+export const load: PageServerLoad = async ({ fetch, locals, url, params }) => {
+	const session = await locals.auth();
+
+	// Redirect to login if not authenticated
+	if (!session?.user?.nickname) {
+		const callbackUrl = encodeURIComponent(url.pathname);
+		throw redirect(302, `/login?callbackUrl=${callbackUrl}`);
+	}
+
+	// Check user group permission
+	if (!session.user.groups?.includes('rezepte_users')) {
+		throw error(403, 'Zugriff verweigert. Du hast keine Berechtigung für diesen Bereich.');
+	}
+
+	try {
+		const res = await fetch('/api/rezepte/translate/untranslated');
+
+		if (!res.ok) {
+			return {
+				untranslated: [],
+				session,
+				recipeLang: params.recipeLang,
+				error: 'Fehler beim Laden der unübersetzten Rezepte'
+			};
+		}
+
+		const untranslated = await res.json();
+
+		return {
+			untranslated,
+			session,
+			recipeLang: params.recipeLang
+		};
+	} catch (e) {
+		return {
+			untranslated: [],
+			session,
+			recipeLang: params.recipeLang,
+			error: 'Fehler beim Laden der unübersetzten Rezepte'
+		};
+	}
+};