fix(cmdutil): return converted YAML bytes directly in formatJSON and prevent nil-pointer panic

[Adityakk9031]

Summary

In \pkg/cmd/cmdutil.go\ (\ormatJSON), when --format yaml\ was requested, the function was writing directly to \opts.Stdout\ and returning (nil, err).

This caused several issues:

1. Nil-pointer dereference panic: If \opts.Stdout\ was nil (e.g. when callers or tests invoked \ormatJSON\ without defaults initialized), calling \opts.Stdout.Write(...)\ triggered a panic.
2. Empty byte slice returned: Callers received an empty []byte, causing callers to lose the formatted output.
3. Broken pagination and streaming: In \ShowJSONIterator, \ormatJSON\ prematurely wrote output to stdout before terminal height calculations and pager setup, resulting in corrupted line counts and empty output streamed to pagers.

Solution

Return []byte(yaml.String()), nil\ directly from \ormatJSON\ in the YAML case, consistent with all other formats (\json, \jsonl,
aw, \pretty). \ShowJSON\ and \ShowJSONIterator\ then handle writing/buffering the returned bytes as intended.

Tests

• Added unit test in \pkg/cmd/cmdutil_test.go\ (\YAMLFormat) verifying that \ormatJSON\ successfully converts JSON to YAML and does not panic when \opts.Stdout\ is nil.