Update changelogs from fern repo (#4291)

Co-authored-by: Swimburger <3382717+Swimburger@users.noreply.github.com>

Author: fern-support

fern/products/sdks/overview/typescript/changelog/2026-03-16.mdx

@@ -1,3 +1,11 @@
+## 3.56.3
+**`(fix):`** Fix TypeScript SDK generator crash when generating WebSocket clients for
+AsyncAPI specs that define a named server (e.g. `servers.production`) with
+a single-URL environment. The `baseUrlId` assigned by the Fern IR converter
+is now silently ignored for single-URL environments since there is only one
+URL to resolve to.
+
+
 ## 3.56.2
 **`(chore):`** Rename the `shouldGenerateWebsocketClients` configuration option to
 `generateWebSocketClients`. The old name is still accepted as a deprecated