feat(codex): expose reasoning mode in webui

[ruizanthony]

Summary

• add a Codex-only reasoning mode picker for standard / pro in the WebUI chat sidebar
• hide the mode control for non-openai-codex providers while preserving the existing reasoning-effort picker unchanged
• persist agent.reasoning_mode and load it only for openai-codex gateway/TUI sessions
• send reasoning.mode only to the Codex Responses backend; non-Codex Responses requests keep their existing payload

Review fixes

• rebuilt the PR as one focused commit on current main
• removed the unrelated commentary-stream test rewrite that raised TypeError
• removed the unrelated WebUI max reasoning-effort change
• added component-level Codex-versus-non-Codex visibility coverage plus a parent-wiring guard

Validation

• scripts/run_tests.sh tests/agent/transports/test_codex_transport.py tests/gateway/test_runtime_config_env_expansion.py tests/hermes_cli/test_config.py tests/test_tui_gateway_server.py tests/run_agent/test_run_agent_codex_responses.py — 629 passed
• npm test -- --run — 74 passed
• npm run typecheck
• npm run build
• ESLint on the five changed WebUI files
• Ruff on the eight changed Python files
• python -m compileall -q agent/transports/codex.py gateway/run.py hermes_cli/config.py tui_gateway/server.py
• git diff --check

Notes

reasoning.mode is validated as standard or pro and is deliberately scoped twice: when loading config for openai-codex, and again when building a Codex-backend request. Other providers continue receiving only their existing reasoning payload.

[teknium1]

Thanks for the focused Codex dashboard work. The feature remains needed: live main's ReasoningPicker defaults showMode to false (web/src/components/ReasoningPicker.tsx:55), and its parent does not pass that prop (web/src/components/ChatSidebar.tsx:345-356).

Problems

• tests/run_agent/test_run_agent_codex_responses.py:726 passes on_commentary_message to _consume_codex_event_stream, but the PR head's function signature (agent/codex_runtime.py:597-606) has no such parameter and this PR does not modify that file. The changed commentary tests will fail with TypeError.
• The branch is substantially stale relative to live main. Main already contains the transport/TUI reasoning-mode pieces (agent/transports/codex.py:292-295), so salvage should avoid replaying those overlapping changes.

Suggested changes

• Remove the unrelated commentary-stream test changes from this PR.
• Re-scope the salvage to the missing ChatSidebar provider/showMode wiring and add a component-level Codex-versus-non-Codex visibility test.

Automated hermes-sweeper review.

[ruizanthony]

Closing intentionally: reasoning.mode=pro is not usable with the openai-codex subscription backend, so exposing this control would be misleading. The local integration has also been removed.