fix(nitro): only compute default integrations when not provided

Align with Bun/Deno/Cloudflare SDKs by guarding the default integrations
computation behind an undefined check instead of relying on spread order.

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

Author: logaretm

packages/nitro/src/sdk.ts

@@ -8,10 +8,13 @@ import { getDefaultIntegrations as getDefaultNodeIntegrations, init as nodeInit
  */
 export function init(options: NodeOptions | undefined = {}): NodeClient | undefined {
   const opts: NodeOptions = {
-    defaultIntegrations: getDefaultIntegrations(options),
     ...options,
   };
 
+  if (opts.defaultIntegrations === undefined) {
+    opts.defaultIntegrations = getDefaultIntegrations(opts);
+  }
+
   applySdkMetadata(opts, 'nitro', ['nitro', 'node']);
 
   const client = nodeInit(opts);