* fix(oauth): force-map responses to config alias not request suffix
Rewrite client-visible model fields using oauth-model-alias Alias from config
(e.g. gpt-5.4-fast) instead of mirroring the requested model string when the
client adds thinking suffixes (e.g. gpt-5.4-fast(high)). Upstream routing
still preserves suffixes on the resolved upstream model.
* test(oauth): gate response rewrite on ForceMapping and document OriginalAlias
- Document that OriginalAlias is only applied when ForceMapping is true
- Set OriginalAlias to config alias only when force-mapping is enabled
- Add tests: no non-stream/stream payload rewrite when ForceMapping is false
* test(oauth): assert disabled force mapping response
a7250275c1