add route matcher to fix /login and /logout routes

Use SvelteKit param matcher to constrain [recipeLang] to only match
'recipes' or 'rezepte', preventing it from catching /login, /logout,
and other non-recipe routes.

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

@@ -0,0 +1,73 @@
+import { redirect, error } from '@sveltejs/kit';
+
+export const actions = {
+    toggleFavorite: async ({ request, locals, url, fetch }) => {
+        const session = await locals.auth();
+        
+        if (!session?.user?.nickname) {
+            throw error(401, 'Authentication required');
+        }
+        
+        const formData = await request.formData();
+        const recipeId = formData.get('recipeId') as string;
+        const isFavorite = formData.get('isFavorite') === 'true';
+        
+        if (!recipeId) {
+            throw error(400, 'Recipe ID required');
+        }
+        
+        try {
+            // Use the existing API endpoint
+            const method = isFavorite ? 'DELETE' : 'POST';
+            const response = await fetch('/api/rezepte/favorites', {
+                method,
+                headers: {
+                    'Content-Type': 'application/json',
+                },
+                body: JSON.stringify({ recipeId }),
+            });
+            
+            if (!response.ok) {
+                const errorData = await response.text();
+                console.error('API error:', response.status, errorData);
+                throw error(response.status, `Failed to toggle favorite: ${errorData}`);
+            }
+            
+            // Redirect back to the same page to refresh the state
+            throw redirect(303, url.pathname);
+        } catch (e) {
+            // If it's a redirect, let it through
+            if (e && typeof e === 'object' && 'status' in e && e.status === 303) {
+                throw e;
+            }
+            console.error('Favorite toggle error:', e);
+            throw error(500, 'Failed to toggle favorite');
+        }
+    },
+    
+    swapYeast: async ({ request, url }) => {
+        const formData = await request.formData();
+        const yeastId = parseInt(formData.get('yeastId') as string);
+
+        // Build new URL
+        const newUrl = new URL(url.pathname, url.origin);
+        
+        // Restore all parameters from the form data (they were submitted as currentParam_*)
+        for (const [key, value] of formData.entries()) {
+            if (key.startsWith('currentParam_')) {
+                const paramName = key.substring('currentParam_'.length);
+                newUrl.searchParams.set(paramName, value as string);
+            }
+        }
+        
+        // Toggle the yeast flag - if it exists, remove it; if not, add it
+        const yeastParam = `y${yeastId}`;
+        if (newUrl.searchParams.has(yeastParam)) {
+            newUrl.searchParams.delete(yeastParam);
+        } else {
+            newUrl.searchParams.set(yeastParam, '1');
+        }
+        
+        throw redirect(303, newUrl.toString());
+    }
+};