update changelogs

Author: Swimburger

fern/products/sdks/overview/typescript/changelog/2025-10-17.mdx

@@ -0,0 +1,8 @@
+## 3.9.2
+**`(fix):`** Match the logic in wire test generation where the static example generation omits the request parameter for empty objects when optional.
+This fixes some wire tests that were failing due to mismatched request bodies.
+
+
+**`(fix):`** Return `undefined` when passing in `undefined` to `toJson` when `useBigInt` is enabled.
+
+