fix: add TTL index to statistics collection for automatic cleanup (#38568)

.changeset/young-humans-stare.md

@@ -0,0 +1,6 @@
+---
+'@rocket.chat/models': patch
+'@rocket.chat/meteor': patch
+---
+
+Adds automatic cleanup of statistics collection with 1-year retention via TTL index.

packages/models/src/models/Statistics.ts

@@ -10,7 +10,10 @@ export class StatisticsRaw extends BaseRaw<IStats> implements IStatisticsModel {
 	}
 
 	protected override modelIndexes(): IndexDescription[] {
-		return [{ key: { createdAt: -1 } }];
+		return [
+			{ key: { createdAt: -1 } },
+			{ key: { createdAt: 1 }, expireAfterSeconds: 365 * 24 * 60 * 60 }, // expire after 1 year
+		];
 	}
 
 	async findLast(): Promise<IStats> {