Support player ping in game telemetry

src/lib/telemetry.ts

@@ -1,6 +1,8 @@
 export interface TelemetryPlayer {
     name: string;
     guid: string;
+    /** Server-measured latency in milliseconds; absent/null when unavailable. */
+    ping?: number | null;
 }
 
 export interface TelemetryPlayerStats extends TelemetryPlayer {
@@ -51,7 +53,13 @@ export function parseGameEvent(value: unknown): GameEvent {
         for (const key of ['name', 'guid'] as const) {
             if (typeof player[key] !== 'string' || !player[key].trim()) throw new Error(`players[${index}].${key} must be a nonempty string`);
         }
-        const identity = { name: player.name as string, guid: player.guid as string };
+        const identity: TelemetryPlayer = { name: player.name as string, guid: player.guid as string };
+        if (player.ping !== undefined) {
+            if (player.ping !== null && (!Number.isSafeInteger(player.ping) || (player.ping as number) < 0)) {
+                throw new Error(`players[${index}].ping must be a nonnegative integer or null`);
+            }
+            identity.ping = player.ping as number | null;
+        }
         if (guids.has(identity.guid)) throw new Error(`players[${index}].guid must be unique within the report`);
         guids.add(identity.guid);
         if (body.event === 'game_start') return identity;