/permissions Full Access session-only confirmation persists approvals_reviewer to config.toml

Bug

In Codex CLI 0.124.0, selecting:

/permissions -> Full Access -> Yes, continue anyway

is described as applying Full Access "for this session", but it also persists approvals_reviewer = "user" to config.toml.

Expected

The session-only confirmation should update the active session state only.

Actual

approvals_reviewer is written to config.toml, which can overwrite a persisted reviewer such as guardian_subagent.

Reproduction

1. Start Codex with a non-Full Access permission state and a persisted reviewer, for example approvals_reviewer = "guardian_subagent".
2. Open /permissions.
3. Select Full Access.
4. In the confirmation prompt, select Yes, continue anyway, whose description is Apply full access for this session.
5. Inspect ~/.codex/config.toml.

Observed locally on codex-cli 0.124.0: the persisted config changed approvals_reviewer to user even though the prompt said the choice was session-scoped.

Patch

I prepared a minimal fix in my fork:

• Commit: https://github.com/decentralizedblack-maker/codex-cli-fork/commit/3ac2fd030
• Compare: https://github.com/decentralizedblack-maker/codex-cli-fork/compare/main...fix/full-access-session-only-permission

The patch adds a session-only UpdateApprovalsReviewerForSession event and uses it for /permissions preset selection. The existing persistent UpdateApprovalsReviewer event remains available for paths that intentionally write approvals_reviewer to config.toml.

I could not open a PR because this repository currently limits pull request creation to collaborators.

Local verification

• git diff --check passed

Not run locally:

• cargo fmt
• cargo test -p codex-tui permissions_full_access_history_cell_emitted_only_after_confirmation

Reason: the local shell used for preparing the patch does not currently have cargo, rustfmt, or just on PATH.