feat(wiki): add tag-based wiki recommendations API

server/models/wikiArticle.js

@@ -0,0 +1,20 @@
+import mongoose from 'mongoose'
+
+const wikiArticleSchema = new mongoose.Schema(
+  {
+    outlineId: { type: String, unique: true, required: true },
+    title: { type: String, required: true },
+    collection: String,
+    url: { type: String, required: true },
+    summary: String,
+    tags: [{ type: String }],
+    publishedAt: Date,
+    permission: String,
+    lastSyncedAt: Date,
+    outlineUpdatedAt: Date
+  },
+  { timestamps: true }
+)
+
+export default mongoose.models.WikiArticle ||
+  mongoose.model('WikiArticle', wikiArticleSchema)