feat: change organisation owner in admin panel (#2047)

Allows changing the owner of an organisation within the admin panel,
useful for support requests to change ownership from a testing account
to the main admin account.

<img width="890" height="431" alt="image"
src="https://github.com/user-attachments/assets/475bbbdd-0f26-4f74-aacf-3e793366551d"
/>

apps/remix/app/routes/_authenticated+/admin+/organisations.$id.tsx

@@ -71,6 +71,23 @@ export default function OrganisationGroupSettingsPage({ params }: Route.Componen
       },
     });
 
+  const { mutateAsync: promoteToOwner, isPending: isPromotingToOwner } =
+    trpc.admin.organisationMember.promoteToOwner.useMutation({
+      onSuccess: () => {
+        toast({
+          title: t`Success`,
+          description: t`Member promoted to owner successfully`,
+        });
+      },
+      onError: () => {
+        toast({
+          title: t`Error`,
+          description: t`We couldn't promote the member to owner. Please try again.`,
+          variant: 'destructive',
+        });
+      },
+    });
+
   const teamsColumns = useMemo(() => {
     return [
       {
@@ -101,6 +118,26 @@ export default function OrganisationGroupSettingsPage({ params }: Route.Componen
           <Link to={`/admin/users/${row.original.user.id}`}>{row.original.user.email}</Link>
         ),
       },
+      {
+        header: t`Actions`,
+        cell: ({ row }) => (
+          <div className="flex justify-end space-x-2">
+            <Button
+              variant="outline"
+              disabled={row.original.userId === organisation?.ownerUserId}
+              loading={isPromotingToOwner}
+              onClick={async () =>
+                promoteToOwner({
+                  organisationId,
+                  userId: row.original.userId,
+                })
+              }
+            >
+              <Trans>Promote to owner</Trans>
+            </Button>
+          </div>
+        ),
+      },
     ] satisfies DataTableColumnDef<TGetAdminOrganisationResponse['members'][number]>[];
   }, [organisation]);