fix: Make filteredUserAttributes optional on RoktKit.init

`KitInterface.init` declares `userAttributes?: AllUserAttributes`, so callers
may omit it. The override required the param, which violated substitutability
once the kit consumed the SDK's authoritative `KitInterface` types instead of
the looser DT shape. Adding `?` is enough — `Record<string, unknown>` is
already a supertype of `AllUserAttributes` on the value side.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: rmi22186

src/Rokt-Kit.ts

@@ -18,6 +18,7 @@
 
 import { Batch, KitInterface, IMParticleUser, SDKEvent } from '@mparticle/web-sdk/internal';
 import type { IUserIdentities } from '@mparticle/web-sdk';
+
 // BaseEvent not re-exported from @mparticle/web-sdk/internal, so we import directly from @mparticle/event-models.
 import { BaseEvent } from '@mparticle/event-models';
 
@@ -1071,7 +1072,7 @@ class RoktKit implements KitInterface {
     _service: unknown,
     testMode: boolean,
     _trackerId: unknown,
-    filteredUserAttributes: Record<string, unknown>,
+    filteredUserAttributes?: Record<string, unknown>,
   ): string {
     const kitSettings = settings as unknown as RoktKitSettings;
     const accountId = kitSettings.accountId;