fix: try to fix gist

src/core/Gist.ts

@@ -114,9 +114,6 @@ export default class Gist {
       comments: commentsMapped,
     };
     this._gistPayload = payload;
-    // `gist` is a nested path (not a sub-schema), so assigning the whole
-    // object via set("gist", payload) mis-casts the inner subdoc arrays.
-    // Set each sub-path individually so Mongoose casts arrays correctly.
     this._model.set("gist.description", payload.description);
     this._model.set("gist.isPublic", payload.isPublic);
     this._model.set("gist.creationDate", payload.creationDate);

src/core/model/anonymizedGists/anonymizedGists.schema.ts

@@ -51,7 +51,10 @@ const AnonymizedGistSchema = new Schema({
         content: String,
         language: String,
         size: Number,
-        type: String,
+        // `type` is a reserved key in Mongoose type declarations; without the
+        // nested `{ type: String }` the whole object is compiled as an array
+        // of strings and file objects are silently dropped on save.
+        type: { type: String },
       },
     ],
     comments: [