fix: add category and favorites filters to all recipe pages

- Move categories logic into Search component for centralization
- Add isLoggedIn prop to SeasonLayout and IconLayout components
- Fix FilterPanel CSS to properly handle hidden favorites filter
- Fix FavoritesFilter to trigger onToggle when checkbox changes
- Update Search effect to track all filter states (category, tags, icon, season, favorites)
- Hide favorites filter on favorites page while maintaining proper grid layout
- All filters now work consistently across entire site

src/routes/[recipeLang=recipeLang]/+page.svelte

@@ -5,6 +5,7 @@
     	import Card from '$lib/components/Card.svelte';
     	import Search from '$lib/components/Search.svelte';
 	import LazyCategory from '$lib/components/LazyCategory.svelte';
+	import { getCategories } from '$lib/js/categories';
     	let { data } = $props<{ data: PageData }>();
     	let current_month = new Date().getMonth() + 1;
 
@@ -21,9 +22,7 @@
 	}
 
 	const isEnglish = $derived(data.lang === 'en');
-	const categories = $derived(isEnglish
-		? ["Main course", "Noodle", "Bread", "Dessert", "Soup", "Side dish", "Salad", "Cake", "Breakfast", "Sauce", "Ingredient", "Drink", "Spread", "Biscuits", "Snack"]
-		: ["Hauptspeise", "Nudel", "Brot", "Dessert", "Suppe", "Beilage", "Salat", "Kuchen", "Frühstück", "Sauce", "Zutat", "Getränk", "Aufstrich", "Guetzli", "Snack"]);
+	const categories = $derived(getCategories(data.lang));
 
 	// Pre-compute category-to-recipes Map for O(1) lookups
 	const recipesByCategory = $derived.by(() => {
@@ -101,7 +100,7 @@ h1{
 <h1>{labels.title}</h1>
 <p class=subheading>{labels.subheading}</p>
 
-<Search lang={data.lang} recipes={data.all_brief} categories={categories} isLoggedIn={!!data.session?.user} onSearchResults={handleSearchResults}></Search>
+<Search lang={data.lang} recipes={data.all_brief} isLoggedIn={!!data.session?.user} onSearchResults={handleSearchResults}></Search>
 
 {#if seasonRecipes.length > 0}
 	<LazyCategory title={labels.inSeason} eager={true}>

src/routes/[recipeLang=recipeLang]/category/[category]/+page.svelte

@@ -35,7 +35,7 @@
 	}
 </style>
 <h1>{label} <q>{data.category}</q>:</h1>
-<Search category={data.category} lang={data.lang} recipes={data.recipes} onSearchResults={handleSearchResults}></Search>
+<Search category={data.category} lang={data.lang} recipes={data.recipes} isLoggedIn={!!data.session?.user} onSearchResults={handleSearchResults}></Search>
 <section>
 <Recipes>
 	{#each rand_array(filteredRecipes) as recipe}

src/routes/[recipeLang=recipeLang]/favorites/+page.svelte

@@ -79,7 +79,7 @@ h1{
     {/if}
 </p>
 
-<Search favoritesOnly={true} lang={data.lang} recipes={data.favorites} onSearchResults={handleSearchResults}></Search>
+<Search favoritesOnly={true} lang={data.lang} recipes={data.favorites} isLoggedIn={!!data.session?.user} onSearchResults={handleSearchResults}></Search>
 
 {#if data.error}
     <p class="empty-state">{labels.errorLoading} {data.error}</p>

src/routes/[recipeLang=recipeLang]/icon/[icon]/+page.svelte

@@ -26,7 +26,7 @@
         return data.season.filter(r => matchedRecipeIds.has(r._id));
     });
 </script>
-<IconLayout icons={data.icons} active_icon={data.icon} routePrefix="/{data.recipeLang}" lang={data.lang} recipes={data.season} onSearchResults={handleSearchResults}>
+<IconLayout icons={data.icons} active_icon={data.icon} routePrefix="/{data.recipeLang}" lang={data.lang} recipes={data.season} isLoggedIn={!!data.session?.user} onSearchResults={handleSearchResults}>
 	{#snippet recipesSlot()}
 		<Recipes>
 			{#each rand_array(filteredRecipes) as recipe}

src/routes/[recipeLang=recipeLang]/season/+page.svelte

@@ -34,7 +34,7 @@
     });
 </script>
 
-<SeasonLayout active_index={current_month-1} {months} routePrefix="/{data.recipeLang}" lang={data.lang} recipes={data.season} onSearchResults={handleSearchResults}>
+<SeasonLayout active_index={current_month-1} {months} routePrefix="/{data.recipeLang}" lang={data.lang} recipes={data.season} isLoggedIn={!!data.session?.user} onSearchResults={handleSearchResults}>
 	{#snippet recipesSlot()}
 		<Recipes>
 			{#each rand_array(filteredRecipes) as recipe}

src/routes/[recipeLang=recipeLang]/tag/[tag]/+page.svelte

@@ -35,7 +35,7 @@
 	}
 </style>
 <h1>{label} <q>{data.tag}</q>:</h1>
-<Search tag={data.tag} lang={data.lang} recipes={data.recipes} onSearchResults={handleSearchResults}></Search>
+<Search tag={data.tag} lang={data.lang} recipes={data.recipes} isLoggedIn={!!data.session?.user} onSearchResults={handleSearchResults}></Search>
 <section>
 <Recipes>
 	{#each rand_array(filteredRecipes) as recipe}