Move towards selection section inventory management

src/SelectionIntMap.hs

@@ -26,9 +26,12 @@ setShownIntMap sm = case sm ^. smRegex of
 initialSelPos :: SelectionIntMap a -> SelectionIntMap a
 initialSelPos sm = sm & smSelPos .~ mi
   where
-    mi = fst <$> ifind t (sm ^. smShownItems)
-    t _ SelectionRegex{} = False
-    t _ si = _siIsSelectable si
+    mi = case sm ^? smShownItems . ix 0 of
+        Nothing -> Nothing
+        Just SelectionRegex {} -> case sm ^? smShownItems . ix 1 of
+            Nothing -> Just 0
+            Just _ -> Just 1
+        _ -> Just 0
 
 -- assumes that at least one item is selectable!
 -- also assumes that the integer is 1 or -1