Add dollar volume fsp config section to display in subchart

piker/ui/_display.py

@@ -932,7 +932,7 @@ async def maybe_open_vlm_display(
 
         async with open_fsp_sidepane(
             linked, {
-                '$_vlm': {
+                'vlm': {
 
                     'params': {
 
@@ -1102,6 +1102,20 @@ async def display_symbol_data(
         # TODO: eventually we'll support some kind of n-compose syntax
         fsp_conf = {
 
+            'dolla_vlm': {
+                'func_name': 'dolla_vlm',
+                'zero_on_step': True,
+                'params': {
+                    'price_func': {
+                        'default_value': 'chl3',
+                        # tell target ``Edit`` widget to not allow
+                        # edits for now.
+                        'widget_kwargs': {'readonly': True},
+                    },
+                },
+                'chart_kwargs': {'style': 'step'}
+            },
+
             'rsi': {
                 'func_name': 'rsi',  # literal python func ref lookup name