Update changelogs from fern repo (#5260)

Co-authored-by: dsinghvi <10870189+dsinghvi@users.noreply.github.com>

Author: fern-support

fern/products/cli-api-reference/cli-changelog/2026-04-30.mdx

@@ -0,0 +1,9 @@
+## 5.1.0
+**`(internal):`** Introduce a simpler TtyAwareLogger local to `cli-v2`. The new logger drops
+legacy behaviours that cli-v2 did not use (`omitOnTTY`, `FERN_SPINNER_STATUS`,
+dynamic `finish` reassignment, `ora` dependency) and exposes a minimal
+`register` / `write` / `takeOverTerminal` / `finish` surface against a
+generic `Paintable` interface. Box-frame rendering moves into `TaskGroup`.
+The legacy `TtyAwareLogger` in `@fern-api/cli-logger` is untouched.
+
+