recipes: restrict to-try page to editors, remove addedBy

- Gate page and API on rezepte_users group instead of any logged-in user
- Remove addedBy field from schema, API POST, and ToTryCard display

src/models/ToTryRecipe.ts

@@ -9,8 +9,7 @@ const ToTryRecipeSchema = new mongoose.Schema(
         label: { type: String, default: '' }
       }
     ],
-    notes: { type: String, default: '' },
-    addedBy: { type: String, required: true }
+    notes: { type: String, default: '' }
   },
   { timestamps: true }
 );