Convert stats to bigints (#909)

Fixes #880

## Description:

Convert numeric stat types to bigint, and serialize those values as
strings.

## Please complete the following:

- [x] I have added screenshots for all UI updates
- [ ] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced
- [x] I understand that submitting code with bugs that could have been
caught through manual testing blocks releases and new features for all
contributors

---------

Co-authored-by: Scott Anderson <662325+scottanderson@users.noreply.github.com>

src/server/Archive.ts

@@ -60,7 +60,7 @@ async function archiveAnalyticsToR2(gameRecord: GameRecord) {
     await r2.putObject({
       Bucket: bucket,
       Key: `${analyticsFolder}/${analyticsKey}`,
-      Body: JSON.stringify(analyticsData),
+      Body: JSON.stringify(analyticsData, replacer),
       ContentType: "application/json",
     });
 
@@ -78,7 +78,7 @@ async function archiveAnalyticsToR2(gameRecord: GameRecord) {
 
 async function archiveFullGameToR2(gameRecord: GameRecord) {
   // Create a deep copy to avoid modifying the original
-  const recordCopy: GameRecord = JSON.parse(JSON.stringify(gameRecord));
+  const recordCopy = structuredClone(gameRecord);
 
   // Players may see this so make sure to clear PII
   recordCopy.info.players.forEach((p) => {
@@ -89,7 +89,7 @@ async function archiveFullGameToR2(gameRecord: GameRecord) {
     await r2.putObject({
       Bucket: bucket,
       Key: `${gameFolder}/${recordCopy.info.gameID}`,
-      Body: JSON.stringify(recordCopy),
+      Body: JSON.stringify(recordCopy, replacer),
       ContentType: "application/json",
     });
   } catch (error) {
@@ -147,3 +147,10 @@ export async function gameRecordExists(gameId: GameID): Promise<boolean> {
     return false;
   }
 }
+
+/**
+ * JSON.stringify replacer function that converts bigint values to strings.
+ */
+export function replacer(_key: string, value: any): any {
+  return typeof value === "bigint" ? value.toString() : value;
+}