Modularize and streamline billing templates; replace _billing_form.html with reusable modals and shared partials, and update styles and interactions for consistency and clarity. billing, feature management, and forms

Refactored club detail templates to modularize common UI components. Standardized layout, interactions, and styles across admin, billing, and feature cards for consistency and reusability.

controlpanel/services/statistics.py

@@ -155,6 +155,20 @@ def onboarding_funnel():
     ]
 
 
+def flags_for_club(club):
+    """Every flag, annotated with whether it is on for this club and why."""
+    enabled_ids = set(club.flags.values_list("pk", flat=True))
+    return [
+        {
+            "flag": flag,
+            "enabled": flag.pk in enabled_ids,
+            # `everyone` overrides club targeting, so the per-club toggle is moot.
+            "overridden": flag.everyone is not None,
+        }
+        for flag in get_waffle_flag_model().objects.order_by("name")
+    ]
+
+
 def flag_adoption():
     """Clubs per feature flag. `everyone` overrides club targeting, so a flag set that
     way is on (or off) everywhere and its club count says nothing — hence `overridden`."""