do not add fnames to the completions more than once; removed local version of completions list

kabuki/widgets/files.py

@@ -13,7 +13,7 @@ class Files(Column):
 
     def __init__(self, folder, title="Files", name=None, sizing_mode="stretch_width"):
         self.folder = folder = Path(folder)
-        self.files = files = [str(i.relative_to(folder)) for i in folder.rglob("*")]
+        files = [str(i.relative_to(folder)) for i in folder.rglob("*")]
 
         lbl =  Div(text=title)
         adjust_margin(lbl, bottom=-10)
@@ -38,8 +38,9 @@ class Files(Column):
                 print("empty filename")
                 return
 
-            self.files.append(fn)
-            self.ai_fname.completions.append(fn)
+            compl = self.ai_fname.completions
+            if fn not in compl:
+                compl.append(fn)
 
             fn = self.folder / fn