* feat(openai): add gpt-5.4 support and priority processing
* feat(openai-codex): add gpt-5.4 oauth support
* fix(openai): preserve provider overrides in gpt-5.4 fallback
* fix(openai-codex): keep xhigh for gpt-5.4 default
* fix(models): preserve configured overrides in list output
* fix(models): close gpt-5.4 integration gaps
* fix(openai): scope service tier to public api
* fix(openai): complete prep followups for gpt-5.4 support (#36590) (thanks @dorukardahan)
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Co-authored-by: Tyler Yust <TYTYYUST@YAHOO.COM>
Merged via maintainer flow after rebase + local gates.
Prepared head SHA: 6cac87cbf97e5f627085787fe5f565778fa223bf
Co-authored-by: loiie45e <15420100+loiie45e@users.noreply.github.com>
Co-authored-by: mbelinky <2406260+mbelinky@users.noreply.github.com>