feat(overview): replace filter panel with add-filter builder and aging column

Swaps the unbounded vertical filter panel for a Polaris-style add-filter
builder (searchable grouped field picker, type-aware value control, applied
chips) and colour-codes the fees column with each member's period-scoped
unpaid-cycle count.

test/support/conn_case.ex

@@ -36,6 +36,7 @@ defmodule MvWeb.ConnCase do
       import Plug.Conn
       import Phoenix.ConnTest
       import MvWeb.ConnCase
+      import MvWeb.FilterBuilderHelpers
     end
   end