fix(observability): capture Claude usage for phase events

[j5ik2o]

Summary

• Capture usage from Claude Code CLI stream-json result events and pass it through providerUsage.
• Share Claude usage normalization between the Claude SDK provider and Claude headless provider.
• Mark Claude SDK responses with incomplete required token fields as usageMissing instead of producing partial usage.

Context

This is stacked on #785 (codex/otel-usage-events-exporter-docs). During local verification, provider: claude emitted phase usage events with usage_missing=true even though Claude Code CLI returned token usage in the stream-json result event. The headless parser was not propagating that usage into the agent response.

Verification

• npm test -- --run src/__tests__/claude-headless-stream-json.test.ts src/__tests__/claude-headless-client.test.ts src/__tests__/claude-executor-structured-output.test.ts
• npm run build
• npm run lint
• Local --provider claude workflow after build emitted usage_missing=false phase usage events with token totals.

[coderabbitai]

Important

Review skipped

Auto reviews are disabled on base/target branches other than the default branch.

Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: ASSERTIVE

Plan: Pro Plus

Run ID: 3bedfc5d-a048-46f0-8d79-35acf9aafa7b

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

Use the checkbox below for a quick retry:

• 🔍 Trigger review

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch codex/fix-claude-headless-usage-events

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}