fix(codex): preserve upstream error headers

[jroth1111]

Summary

Preserve upstream response headers on Codex HTTP errors and parse standard Retry-After values before returning the error to the auth/retry and API layers.

Fixes #4633.

Root cause

The Codex WebSocket error path already returns statusErrWithHeaders, but the HTTP execute, streaming bootstrap, and image endpoints called newCodexStatusErr(status, body). That constructor retained only the status and response body.

Consequently:

• numeric or HTTP-date Retry-After headers could not influence retry scheduling;
• safe correlation headers such as X-Request-Id were unavailable to optional downstream header passthrough;
• HTTP and WebSocket Codex errors exposed inconsistent metadata.

Changes

• Add newCodexStatusErrWithHeaders for Codex HTTP failures.
• Preserve an immutable clone of the upstream headers.
• Parse RFC-compatible Retry-After delta-seconds and HTTP-date values.
• Keep body-derived usage reset metadata authoritative when both body and header hints exist.
• Use the header-aware error at all Codex HTTP non-2xx call sites:
  • normal execute paths;
  • streaming bootstrap;
  • image generation/edit/variation paths.
• Add constructor-level and real HTTP executor regression coverage for normal and streaming requests.

Downstream header exposure remains governed by the existing passthrough-headers setting and now passes through FilterUpstreamHeaders; Retry-After still participates in internal 408/5xx cooldown scheduling even when passthrough is disabled. Correlation headers are exposed only when passthrough is enabled.

Validation

• go test ./internal/runtime/executor
• go test ./sdk/cliproxy/auth ./sdk/api/handlers
• go vet ./internal/runtime/executor ./sdk/cliproxy/auth ./sdk/api/handlers
• go build ./...
• go test ./...
• git diff --check

All passed against current dev.

[chatgpt-codex-connector]

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[chatgpt-codex-connector]

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Reviewed commit: d530e39a48

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
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If Codex has suggestions, it will comment; otherwise it will react with 👍.

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[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: 0dc8724902

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".