Remove paid field from members

Remove paid field from Member resource, database migration,
tests, seeds, and UI. This field is no longer needed as payment
status is now tracked via membership fee cycles.

lib/mv_web/live/member_live/index.ex

@@ -819,7 +819,7 @@ defmodule MvWeb.MemberLive.Index do
   defp valid_sort_field?(field) when is_atom(field) do
     # All member fields are sortable, but we exclude some that don't make sense
     # :id is not in member_fields, but we don't want to sort by it anyway
-    non_sortable_fields = [:notes, :paid]
+    non_sortable_fields = [:notes]
     valid_fields = Mv.Constants.member_fields() -- non_sortable_fields
 
     field in valid_fields or custom_field_sort?(field)

lib/mv_web/live/member_live/index.html.heex

@@ -307,14 +307,6 @@
     >
       {MvWeb.MemberLive.Index.format_date(member.join_date)}
     </:col>
-    <:col :let={member} :if={:paid in @member_fields_visible} label={gettext("Paid")}>
-      <span class={[
-        "badge",
-        if(member.paid == true, do: "badge-success", else: "badge-error")
-      ]}>
-        {if member.paid == true, do: gettext("Yes"), else: gettext("No")}
-      </span>
-    </:col>
     <:col
       :let={member}
       label={