OpenAI Agents traced in LLM Observability; custom agentless endpoints for feature flags

Features

• LLM Observability: Add support for OpenAI Agents (trace-processor) #8044
• span-stats: Encode SpanKind and GRPCStatusCode in v0.6 stats payload #9190

Fixes

• Feature Flags: Allow custom agentless endpoints #9481
• General: Make peer service finalization idempotent #9364
• LLM Observability: Address OpenAI Agents review feedback #9526
• LLM Observability: Format AI SDK rich tool results #9399
• LLM Observability: Llm observability traces have custom trace IDs #9460
• standalone: Stamp _dd.apm.enabled on every span #9506
• Test Optimization: Harden validation workflow #9431
• Test Optimization: Reject malformed settings policies #9362
• webpack: Opt out of typescript auto resolve #9521

Internal (CI, Testing, Benchmarking)

• aws-sdk: Disable clock skew correction in the Lambda spec #9537
• release: Exclude release proposal branches from license auto-commit #9522
• Test Optimization: Cover worker thread preload #9528