OpenAI OAuth 2.0 Authorization

Securely integrate OpenAI services into the Inference API using standardized OAuth 2.0 client credentials authorization.

**What the feature is**
A standardized OAuth 2.0 client credentials authorization flow for integrating OpenAI services into the inference API, replacing reliance on traditional API keys.

**Who is this feature for**
Developers, security administrators, and enterprise organizations running AI models that need stronger authorization controls.

**Expected outcome**
API keys are static and harder to govern at enterprise scale. Moving to a token-exchanging authorization model significantly strengthens security compliance for organizations that need tighter control over how credentials are issued and rotated.

**Key user stories / use cases**
Enterprise security teams enforcing token-based authorization for OpenAI connections instead of managing long-lived API keys.