## Why
`unix_escalation.rs` checks a session-scoped approval cache before
prompting again for an execve-intercepted skill script. Without also
recording `ReviewDecision::ApprovedForSession`, that cache never gets
populated, so the same skill script can still trigger repeated approval
prompts within one session.
## What Changed
- Add `execve_session_approvals` to `SessionServices` so the session can
track approved skill script paths.
- Record the script path when a skill-script prompt returns
`ReviewDecision::ApprovedForSession`, but only for the skill-script path
rather than broader prefix-rule approvals.
- Reuse the cached approval on later execve callbacks by treating an
already-approved skill script as `Decision::Allow`.
---
[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/12756).
* #12758
* __->__ #12756
Michael Bolin
93efcfd50d