Redesign search tab, add category cards, recent recipes, and complete German translations

Overhaul SearchTabView with search history, empty/no-results states, and dynamic
navigation title. Extract CategoryCardView and RecentRecipesSection into standalone
views. Update RecipeTabView, RecipeListView, RecipeCardView, and MainView for the
modernized UI. Add all 12 missing German translations in Localizable.xcstrings.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Nextcloud Cookbook iOS Client/AppState.swift

@@ -16,6 +16,8 @@ import UIKit
     @Published var recipes: [String: [Recipe]] = [:]
     @Published var recipeDetails: [Int: RecipeDetail] = [:]
     @Published var timers: [String: RecipeTimer] = [:]
+    @Published var categoryImages: [String: UIImage] = [:]
+    @Published var recentRecipes: [Recipe] = []
     var recipeImages: [Int: [String: UIImage]] = [:]
     var imagesNeedUpdate: [Int: [String: Bool]] = [:]
     var lastUpdates: [String: Date] = [:]
@@ -304,6 +306,47 @@ import UIKit
         return []
     }
 
+    // MARK: - Category images
+
+    func getCategoryImage(for categoryName: String) async {
+        guard categoryImages[categoryName] == nil else { return }
+        // Ensure recipes for this category are loaded
+        if self.recipes[categoryName] == nil || self.recipes[categoryName]!.isEmpty {
+            await getCategory(named: categoryName, fetchMode: .preferLocal)
+        }
+        guard let recipes = self.recipes[categoryName], !recipes.isEmpty else { return }
+        for recipe in recipes {
+            if let image = await getImage(id: recipe.recipe_id, size: .THUMB, fetchMode: .preferLocal) {
+                self.categoryImages[categoryName] = image
+                return
+            }
+        }
+    }
+
+    // MARK: - Recent recipes
+
+    func addToRecentRecipes(_ recipe: Recipe) {
+        recentRecipes.removeAll { $0.recipe_id == recipe.recipe_id }
+        recentRecipes.insert(recipe, at: 0)
+        if recentRecipes.count > 10 {
+            recentRecipes = Array(recentRecipes.prefix(10))
+        }
+        Task {
+            await saveLocal(recentRecipes, path: "recent_recipes.data")
+        }
+    }
+
+    func loadRecentRecipes() async {
+        if let loaded: [Recipe] = await loadLocal(path: "recent_recipes.data") {
+            self.recentRecipes = loaded
+        }
+    }
+
+    func clearRecentRecipes() {
+        recentRecipes = []
+        dataStore.delete(path: "recent_recipes.data")
+    }
+
     // MARK: - Data management
 
     func deleteAllData() {