fix(core): validate YAML golden output

[ousamabenyounes]

Community Note

• Please vote on this pull request by adding a 👍 reaction to the original pull request comment to help the community and maintainers prioritize this request.
• Please do not leave "+1" or other comments that do not add relevant new information or questions, as they generate extra noise for pull request followers and do not help prioritize the request.

Closes #5184

Summary

• render and validate YAML stdout and stderr in the golden-test harness alongside JSON
• preserve custom JSON marshaling when YAML-printing CLI errors, including empty errors
• regenerate the affected golden snapshots and normalize temporary config paths in YAML

Test verification (RED → GREEN)

• RED: the focused test fails on upstream main because YAML sections are absent; the empty CliError case also exposes the YAML-printer panic
• GREEN: all three focused YAML golden cases pass with this patch
• full local suite: mise run ci (2,604 Go tests passed, 17 existing skips; 9 WASM tests passed; all build and lint tasks passed)
• changed-line coverage: 100% (37/37 production lines)
• reverting the production patch makes all three focused YAML golden cases fail

NONE

[elwinar]

This is neither a bug, nor a feature we're interested in at this time.