## What changed
- Add `--codex-ui-plugin-process` to `codex-code-mode-host` and a typed protocol for initializing, invoking, and closing UI plugin isolates.
- Support persistent module state and string results from synchronous or promise-based exports across up to 32 isolates in one helper process.
- Require sandbox-enabled V8 with JIT disabled, restrict executable loading and globals, and enforce execution deadlines and per-instance queue, source, result, and promise limits.
- Close affected isolates on script failures, cancellation, or overload, and return bounded script diagnostics.
- Bump the helper handshake to version 3 and increase the maximum frame size to 1 MiB.
## Testing
Add wire-level integration tests and runtime unit tests covering promise settlement, cancellation, loading restrictions, diagnostics, failure isolation, capacity reuse, transport bounds, and watchdog synchronization. Add CLI tests for argument validation before helper startup.
GitOrigin-RevId: bad6a57c84d9197c1fd76a78cf060502c5bc8bb8
## What changed
- Add `codex-plugin-host` to launch a helper with a cleared environment, verify its readiness handshake, and expose framed stdin/stdout pipes with a 256 KiB frame limit and write backpressure.
- Support startup cancellation and process-group cleanup, retaining exit status and the last 16 KiB of stderr while omitting raw diagnostics from `Debug` output.
- Extend the Bazel crate macro to support test-only binaries and fixture entry points outside `src/`.
## Testing
Add process integration tests for framed communication, startup cancellation, helper and descendant cleanup, repeated close calls, and bounded diagnostics from startup and runtime failures.
GitOrigin-RevId: ed539e7899af06ee83a0d8c2d0ea8cec10f19afb
Joe Savona