fix(billing): treat missing seats addon as supported

src/routes/(console)/apply-credit/+page.svelte

@@ -316,7 +316,7 @@
                         {/if}
 
                         <!-- show invite members -->
-                        {#if selectedOrgId && !selectedOrg?.billingPlanDetails.addons.seats.supported}
+                        {#if selectedOrgId && !(selectedOrg?.billingPlanDetails?.addons?.seats?.supported ?? true)}
                             {#if selectedOrgId === newOrgId}
                                 <InputText
                                     label="Organization name"

src/routes/(console)/organization-[organization]/header.svelte

@@ -151,7 +151,7 @@
                                 </Button>
                             </div>
                             <div slot="tooltip">
-                                {!organization?.billingPlanDetails.addons.seats.supported
+                                {!(organization?.billingPlanDetails?.addons?.seats?.supported ?? true)
                                     ? 'Upgrade to add more members'
                                     : `You've reached the members limit for the ${
                                           organization?.billingPlanDetails.name

src/routes/(console)/organization-[organization]/usage/[[invoice]]/totalMembers.svelte

@@ -12,14 +12,14 @@
 
     $: total = members?.total ?? 0;
     $: organizationMembersSupported =
-        !$organization?.billingPlanDetails.addons.seats.supported; /* false on free */
+        $organization?.billingPlanDetails?.addons?.seats?.supported ?? true; /* false on free */
 </script>
 
 <CardGrid>
     <svelte:fragment slot="title">Members</svelte:fragment>
     The number of members in your organization.
     <svelte:fragment slot="aside">
-        {#if !organizationMembersSupported}
+        {#if organizationMembersSupported}
             <div class="u-flex u-flex-vertical">
                 <Layout.Stack direction="row" justifyContent="space-between">
                     <Layout.Stack gap="s" direction="row" alignItems="center">