fix(sdk): cancel Codex responses resolved during publish

[ross-rl]

Summary

• establish one request-lifetime controller for every recognized Codex server request
• retain serverRequest/resolved tracking through handler execution and final result or error publication
• abort in-flight default, custom-handler, and fallback-error responses when Codex clears the request first
• suppress stale fallback responses after external resolution
• cover custom result, handler rejection, and default-response publication races

Tests

• bun run check
• bun run typecheck
• bun run build
• bun run test (25 files, 590 tests)

[reflex-loop]

✅ Reflex agent status: Completed

The agent completed its work.

This PR was created by Reflex.

View the agent run →

_{This comment updates in place as the agent works.}