feat: add PWA offline support for recipe pages

- Add service worker with caching for build assets, static files, images, and pages
- Add IndexedDB storage for recipes (brief and full data)
- Add offline-db API endpoint for bulk recipe download
- Add offline sync button component in header
- Add offline-shell page for direct navigation fallback
- Pre-cache __data.json for client-side navigation
- Add +page.ts universal load functions with IndexedDB fallback
- Add PWA manifest and icons for installability
- Update recipe page to handle missing data gracefully

src/types/types.ts

@@ -87,6 +87,19 @@ export type TranslatedRecipeType = {
   note?: string;
   category: string;
   tags?: string[];
+  portions?: string;
+  preparation?: string;
+  cooking?: string;
+  total_time?: string;
+  baking?: {
+    temperature?: string;
+    length?: string;
+    mode?: string;
+  };
+  fermentation?: {
+    bulk?: string;
+    final?: string;
+  };
   ingredients?: IngredientItem[];
   instructions?: InstructionItem[];
   images?: [{