recipes: add shared "to try" list for external recipes

Household-shared list of external recipes to try, with name, multiple
links, and optional notes. Includes add/edit/delete with confirmation.
Linked from the favorites page via a styled pill button.

src/models/ToTryRecipe.ts

@@ -0,0 +1,18 @@
+import mongoose from 'mongoose';
+
+const ToTryRecipeSchema = new mongoose.Schema(
+  {
+    name: { type: String, required: true, trim: true },
+    links: [
+      {
+        url: { type: String, required: true },
+        label: { type: String, default: '' }
+      }
+    ],
+    notes: { type: String, default: '' },
+    addedBy: { type: String, required: true }
+  },
+  { timestamps: true }
+);
+
+export const ToTryRecipe = mongoose.model('ToTryRecipe', ToTryRecipeSchema);