programs: sane-sandboxed: move parseArgsExtra to outer scope; improve docs

modules/programs/sane-sandboxed

@@ -118,8 +118,8 @@ ensureTrailingSlash() {
 
 ## parse CLI args into the variables declared above
 ## args not intended for this helper are put into $parseArgsExtra
+parseArgsExtra=()
 parseArgs() {
-  parseArgsExtra=()
   while [ "$#" -ne 0 ]; do
     _arg="$1"
     shift
@@ -215,6 +215,8 @@ parseArgs() {
         paths+=("$_path")
         ;;
       (--sane-sandbox-profile)
+        # load the profile *immediately*, inline.
+        # this way, user arguments which come later on the CLI can override any profile config, v.s. if profile loading were defered.
         tryLoadProfileByName "$1"
         shift
         ;;