Use a `unit_prefix: str` (like u or $) on health bar

piker/ui/_forms.py

@@ -703,7 +703,8 @@ def mk_fill_status_bar(
     )
 
     bottom_label = form.add_field_label(
-        'x: {step_size}',
+        # 'x: {step_size}',
+       '{unit_prefix}: {step_size}',
         font_size=bar_label_font_size,
         font_color='gunmetal',
     )

piker/ui/_position.py

@@ -344,7 +344,10 @@ class SettingsPane:
         dsize = tracker.live_pp.dsize
 
         # READ out settings and update the status UI / settings widgets
-        suffix = {'currency': ' $', 'units': ' u'}[alloc.size_unit]
+        unit_char: str = {
+            'currency': '$',
+            'units': 'u',
+        }[alloc.size_unit]
         size_unit, limit = alloc.limit_info()
 
         step_size, currency_per_slot = alloc.step_sizes()
@@ -358,10 +361,11 @@ class SettingsPane:
             self.apply_setting('limit', limit)
 
         self.step_label.format(
-            step_size=str(humanize(step_size)) + suffix
+            unit_prefix=unit_char,
+            step_size=str(humanize(step_size))
         )
         self.limit_label.format(
-            limit=str(humanize(limit)) + suffix
+            limit=f'{unit_char}: {str(humanize(limit))}'
         )
 
         # update size unit in UI