Update changelogs from fern repo (#4270)

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