fix(node-sdk): deflake should stream preferences test

The `Preferences > should stream preferences` test ended its stream on a
fixed 100ms timer, far shorter than the 2000ms used by every other
streaming test. The two HmacKeyUpdate events depend on network
propagation of newly-registered installations, so the 4th update
frequently arrived after the 100ms window, ending the stream early and
failing with `expected 3 to be 4`.

Collect updates until all 4 expected preferences arrive, then end the
stream, with a generous 10s safety-net timeout so a genuine regression
fails with the same clear assertion instead of hanging.

Resolves #3831

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: insipx

sdks/js/node-sdk/test/Preferences.test.ts

@@ -205,14 +205,25 @@ describe("Preferences", () => {
     await client2.conversations.syncAll();
     await sleep(1000);
 
-    setTimeout(() => {
+    const preferences: UserPreferenceUpdate[] = [];
+
+    // Safety net: end the stream if the expected updates never arrive, so the
+    // assertion below fails clearly instead of the test hanging until timeout.
+    // The HmacKeyUpdate events depend on network propagation, so we collect
+    // until we have all 4 expected updates rather than ending on a fixed timer.
+    const endTimeout = setTimeout(() => {
       void stream.end();
-    }, 100);
+    }, 10000);
 
-    const preferences: UserPreferenceUpdate[] = [];
     for await (const update of stream) {
       preferences.push(...update);
+      if (preferences.length >= 4) {
+        break;
+      }
     }
+    clearTimeout(endTimeout);
+    await stream.end();
+
     expect(preferences.length).toBe(4);
     const consentUpdate1 = preferences[0] as Extract<
       UserPreferenceUpdate,