add English translation support for recipes with DeepL integration

- Add embedded translations schema to Recipe model with English support
- Create DeepL translation service with batch translation and change detection
- Build translation approval UI with side-by-side editing for all recipe fields
- Integrate translation workflow into add/edit pages with field comparison
- Create complete English recipe routes at /recipes/* mirroring German structure
- Add language switcher component with hreflang SEO tags
- Support image loading from German short_name for English recipes
- Add English API endpoints for all recipe filters (category, tag, icon, season)
- Include layout with English navigation header for all recipe subroutes

src/types/types.ts

@@ -1,3 +1,44 @@
+// Translation status enum
+export type TranslationStatus = 'pending' | 'approved' | 'needs_update';
+
+// Translation metadata for tracking changes
+export type TranslationMetadata = {
+  lastModifiedGerman?: Date;
+  fieldsModifiedSinceTranslation?: string[];
+};
+
+// Translated recipe type (English version)
+export type TranslatedRecipeType = {
+  short_name: string;
+  name: string;
+  description: string;
+  preamble?: string;
+  addendum?: string;
+  note?: string;
+  category: string;
+  tags?: string[];
+  ingredients?: [{
+    name?: string;
+    list: [{
+      name: string;
+      unit: string;
+      amount: string;
+    }]
+  }];
+  instructions?: [{
+    name?: string;
+    steps: string[];
+  }];
+  images?: [{
+    alt: string;
+    caption?: string;
+  }];
+  translationStatus: TranslationStatus;
+  lastTranslated?: Date;
+  changedFields?: string[];
+};
+
+// Full recipe model with translations
 export type RecipeModelType = {
   _id: string;
   short_name: string;
@@ -41,6 +82,10 @@ export type RecipeModelType = {
   }]
   preamble?: String
   addendum?: string
+  translations?: {
+    en?: TranslatedRecipeType;
+  };
+  translationMetadata?: TranslationMetadata;
 };
 
 export type BriefRecipeType = {