server: change JSON.parse/stringify to structuredClone

structuredClone is more typesafe than using JSON.parse and
JSON.stringify.

Now that Node 18.x is the new baseline, this should be safe to use now.

See https://developer.mozilla.org/en-US/docs/Web/API/structuredClone
for details.

packages/backend/src/models/repositories/drive-file.ts

@@ -27,9 +27,7 @@ export const DriveFileRepository = db.getRepository(DriveFile).extend({
 
 	getPublicProperties(file: DriveFile): DriveFile['properties'] {
 		if (file.properties.orientation != null) {
-			// TODO
-			//const properties = structuredClone(file.properties);
-			const properties = JSON.parse(JSON.stringify(file.properties));
+			const properties = structuredClone(file.properties);
 			if (file.properties.orientation >= 5) {
 				[properties.width, properties.height] = [properties.height, properties.width];
 			}

packages/backend/src/server/web/manifest.ts

@@ -5,7 +5,7 @@ import manifest from './manifest.json' assert { type: 'json' };
 export const manifestHandler = async (ctx: Koa.Context): Promise<void> => {
 	// TODO
 	//const res = structuredClone(manifest);
-	const res = JSON.parse(JSON.stringify(manifest));
+	const res = structuredClone(manifest);
 
 	const instance = await fetchMeta(true);
 

packages/backend/src/services/relay.ts

@@ -96,9 +96,7 @@ export async function deliverToRelays(user: { id: User['id']; host: null; }, act
 	const relays = await relaysCache.fetch('');
 	if (relays == null || relays.length === 0) return;
 
-	// TODO
-	//const copy = structuredClone(activity);
-	const copy = JSON.parse(JSON.stringify(activity));
+	const copy = structuredClone(activity);
 	if (!copy.to) copy.to = ['https://www.w3.org/ns/activitystreams#Public'];
 
 	const signed = await attachLdSignature(copy, user);