docs: add #167 sandbox fix to v0.48.1 release notes

Author: ualtinok

.alfonso/release-notes/v0.48.1.md

@@ -2,6 +2,10 @@
 
 Patch release: correctness and performance fixes. No new features, no config changes.
 
+## Sandbox (beta)
+
+- Fixed the Linux sandbox breaking exit-code recording for every sandboxed bash command. The Landlock launcher's descriptor-hygiene step closed the two file descriptors AFT uses to record a command's exit status, so sandboxed commands finished with no exit code (and a command interrupted mid-git could leave a stale `.git/index.lock` behind). The hygiene step now preserves those descriptors, and a Linux CI test runs a real sandboxed command end-to-end to verify exit codes are recorded. macOS was unaffected. (#167)
+
 ## Search
 
 - Cross-project `aft_search` on a repository that has no AFT index now returns a bounded lexical scan with a disclosure instead of failing with `not_indexed`. The error dead-ended agents into shell fallbacks; the same situation in `grep` already degraded gracefully, and the two tools now behave consistently. Semantic ranking still requires an index built by a session in that project, and the disclosure says so. (#166)