Validate access to derived host roots

docs/roadmap/remediation.md

@@ -133,6 +133,8 @@ and downstream consumers. Findings 1–4 remain open.
 
 ## Finding 5 — Derived host roots skip standalone access validation
 
+**Status** — Complete. Derived and explicit standalone contexts share the host root open and close checks. The permission regression passed for both paths.
+
 **Priority P2.** When a companion binds to the main context with imports
 disabled, `acquireStandaloneInput` checks the resolved directories with
 `Stat`. An equivalent explicit context goes through