Update changelogs from fern repo (#4267)

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

Author: fern-support

fern/products/cli-api-reference/cli-changelog/2026-03-13.mdx

@@ -1,3 +1,14 @@
+## 4.29.0
+**`(feat):`** Add AI changelog rollup for multi-chunk diff analysis. When large diffs
+are split into multiple chunks, the resulting changelog entries are now
+consolidated via a dedicated AI call that deduplicates repetitive bullets,
+groups changes under Keep a Changelog headers (Breaking Changes, Added,
+Changed, Fixed), and produces a structured PR description with
+Before/After code fences for breaking changes. Also adds a
+`version_bump_reason` field to AI analysis responses, providing an
+explicit one-sentence justification for why MAJOR/MINOR/PATCH was chosen.
+
+
 ## 4.28.0
 **`(feat):`** Add `coerce-consts-to` setting for controlling how OpenAPI/AsyncAPI
 `const` values are represented. Set to `literals` to convert them directly

fern/products/sdks/overview/typescript/changelog/2026-03-13.mdx

@@ -0,0 +1,11 @@
+## 3.55.0
+**`(feat):`** Add a passthrough `fetch` method to the root client class of all generated TypeScript SDKs.
+The method mimics the standard `fetch` API while automatically applying the SDK's configured
+authentication, base URL resolution, retry logic with exponential backoff, request timeouts,
+custom headers, and logging. This allows users to make requests to endpoints not yet exposed
+in the SDK definition (e.g., new public endpoints, closed beta endpoints) without additional
+setup. The method accepts three parameters: `url` (string or relative path), `init` (standard
+`RequestInit`), and `requestOptions` (SDK-specific overrides for timeout, retries, headers,
+and abort signal).
+
+