fix(codex): omit compact client metadata

[Tr0sT]

Summary

• omit client_metadata for Codex /responses/compact requests
• skip Codex installation metadata injection on the compact endpoint
  while keeping it for normal /responses calls
• add a regression test for compact request transformation

Related Issues

• Related to Fix Codex /responses/compact passthrough #1777
• Related to fix: increase timeout and add error logging for context summarization #1363
• Related to fix: Dynamic Context Compaction #1368

Context

This is another compact-specific Codex passthrough cleanup. We
already fixed /responses/compact handling in #1777 by removing
unsupported store and forcing the compact endpoint through the non-
streaming JSON path. Earlier compaction-related work in #1363 and
#1368 focused on context handoff timeouts/limits.

The new failure was a different unsupported field:

Error running remote compact task: {"error":{"message":"[400]:
Unknown parameter:
client_metadata","type":"invalid_request_error","code":"bad_request"}
}

It came back because the Codex executor still reused the normal / responses metadata decoration for compact requests. That decoration
is useful for regular Codex Responses calls, but /responses/compact
has a stricter schema and rejects client_metadata entirely, just
like it rejected store in #1777.

Validation

• npm run lint
• npm run test:unit
• npm run test:coverage
• Coverage is still >= 60% for statements, lines, functions,
  and branches
• SonarQube PR analysis is green or any remaining issues are
  explicitly documented below

Tests Added Or Updated

• tests/unit/executor-codex.test.ts adds coverage that compact
  requests drop incoming client_metadata and do not receive injected
  Codex installation metadata.

Coverage Notes

The production change is limited to open-sse/executors/codex.ts.
The new unit test covers the compact branch of
CodexExecutor.transformRequest, while the existing metadata test
continues to cover normal /responses behavior.

Reviewer Notes

The change intentionally keeps client_metadata on regular Codex / responses requests. Only /responses/compact strips it because the
compact endpoint rejects the parameter upstream.

[gemini-code-assist]

Code Review

This pull request modifies the CodexExecutor to ensure that client_metadata is omitted from the request body when processing compact requests. This is implemented by explicitly deleting the field and guarding the metadata application logic with a conditional check. A new unit test has been added to verify that metadata is correctly stripped for the compact endpoint. I have no feedback to provide.

[diegosouzapw]

Thanks @Tr0sT for this great contribution! 🎉 It's now officially merged into the release/v3.7.6 branch and will be part of the next release. We deeply appreciate your effort!

[diegosouzapw]

Thanks @Tr0sT for this great contribution! 🎉 It's now officially merged into the release/v3.7.6 branch and will be part of the next release. We deeply appreciate your effort!