Add persistent player leaderboards from game telemetry

src/lib/telemetry.ts

@@ -27,6 +27,7 @@ export function parseGameEvent(value: unknown): GameEvent {
         if (typeof body[key] !== 'string' || !body[key].trim() || body[key].length > 255) throw new Error(`${key} must be a nonempty string (up to 255 characters)`);
     }
     if (!Array.isArray(body.players)) throw new Error('players must be an array');
+    const guids = new Set<string>();
     const players = body.players.map((value, index) => {
         if (!value || typeof value !== 'object' || Array.isArray(value)) throw new Error(`players[${index}] must be an object`);
         const player = value as Record<string, unknown>;
@@ -34,6 +35,8 @@ export function parseGameEvent(value: unknown): GameEvent {
             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 };
+        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;
         const stats = {} as Omit<TelemetryPlayerStats, keyof TelemetryPlayer>;
         for (const key of ['kills', 'headshots', 'downs', 'revives', 'score'] as const) {