test(instrumentation-js): validate Together AI OTel 2.x spans

[Nightingalelyy]

Summary

• add real OpenTelemetry 2.x OTLP JSON serialization coverage for Together AI image, rerank, speech, transcription, and translation spans
• assert canonical Respan model, request type, input, output, and token-usage fields survive serialization
• add a none release intent because this change strengthens contract coverage without changing runtime behavior

Why.

The audit showed that Together AI non-chat spans contain canonical model and usage attributes before export, while the platform does not currently populate those values in its top-level non-chat columns. The correct package-side fix is to lock down the canonical OTLP wire contract rather than add unsupported aliases or change span types.

Impact.

This prevents regressions in non-chat attribute export and makes the remaining ingestion boundary explicit. There is no production runtime or package-version change.

The corresponding example-project fixes are local to respan-example-projects: exact shared-marker metadata for Vercel AI SDK, awaited Vertex AI shutdown, and complete streamed workflow capture.

Validation

• Together AI package tests: 9/9

• Vercel AI SDK package tests: 47/47

• Vertex AI package tests: 7/7

• all three package builds and npm pack --dry-run checks passed

• all 18 corresponding examples passed with marker otel2-fix-js-group-05-20260815T144725Z

• MCP audit: 18/18 trace trees and 58/58 individual span records inspected; one root per trace, matching counts, no orphans, cycles, or duplicates

• release inventory, release intent, and diff checks passed

• Full source and paired-example diffs were audited against every applicable document under contribution/; canonical span fields, OTel attribute shapes, release-intent/version ownership, and package boundaries have no remaining package-owned violation.

External follow-ups

• Together AI examples are mock-backed and Vertex AI examples use explicit fake mode because the repository environment does not provide those providers' live credentials.

Companion examples

• fix(examples-js): validate Vercel AI SDK and Vertex AI OTel 2.x spans respan-example-projects#52

[greptile-apps]

Your trial has ended. Reactivate Greptile to resume code reviews.