fix: block sensitive symlink targets

internal/codexhome/bounds.go

@@ -101,6 +101,9 @@ func rejectSymlinkEscape(home string, candidate string) error {
 		if !isInside(evaluatedHome, currentEvaluated) {
 			return ErrOutsideCodexHome
 		}
+		if IsForbidden(currentEvaluated, evaluatedHome) {
+			return ErrForbiddenPath
+		}
 	}
 	return nil
 }