feat: allow disabling registration

lib/mv_web/live/global_settings_live.ex

@@ -11,12 +11,14 @@ defmodule MvWeb.GlobalSettingsLive do
 
   ## Settings
   - `club_name` - The name of the association/club (required)
+  - `registration_enabled` - Whether direct registration via /register is allowed
   - `join_form_enabled` - Whether the public /join page is active
   - `join_form_field_ids` - Ordered list of field IDs shown on the join form
   - `join_form_field_required` - Map of field ID => required boolean
 
   ## Events
   - `validate` / `save` - Club settings form
+  - `toggle_registration_enabled` - Enable/disable direct registration (/register)
   - `toggle_join_form_enabled` - Enable/disable the join form
   - `add_join_form_field` / `remove_join_form_field` - Manage join form fields
   - `toggle_join_form_field_required` - Toggle required flag per field
@@ -80,6 +82,7 @@ defmodule MvWeb.GlobalSettingsLive do
       |> assign(:oidc_only_env_set, Mv.Config.oidc_only_env_set?())
       |> assign(:oidc_configured, Mv.Config.oidc_configured?())
       |> assign(:oidc_client_secret_set, Mv.Config.oidc_client_secret_set?())
+      |> assign(:registration_enabled, settings.registration_enabled != false)
       |> assign(:smtp_env_configured, Mv.Config.smtp_env_configured?())
       |> assign(:smtp_host_env_set, Mv.Config.smtp_host_env_set?())
       |> assign(:smtp_port_env_set, Mv.Config.smtp_port_env_set?())
@@ -607,8 +610,29 @@ defmodule MvWeb.GlobalSettingsLive do
             <% end %>
           </.form>
         </.form_section>
-        <%!-- OIDC Section --%>
-        <.form_section title={gettext("OIDC (Single Sign-On)")}>
+        <%!-- Authentication: Direct registration + OIDC --%>
+        <.form_section title={gettext("Authentication")}>
+          <h3 class="font-medium mb-3">{gettext("Direct registration")}</h3>
+          <p class="text-sm text-base-content/70 mb-4">
+            {gettext(
+              "If disabled, users cannot sign up via /register; sign-in and the join form remain available."
+            )}
+          </p>
+          <div class="flex items-center gap-3 mb-6">
+            <input
+              type="checkbox"
+              id="registration-enabled-checkbox"
+              class="checkbox checkbox-sm"
+              checked={@registration_enabled}
+              phx-click="toggle_registration_enabled"
+              aria-label={gettext("Allow direct registration (/register)")}
+            />
+            <label for="registration-enabled-checkbox" class="cursor-pointer font-medium">
+              {gettext("Allow direct registration (/register)")}
+            </label>
+          </div>
+
+          <h3 class="font-medium mb-3">{gettext("OIDC (Single Sign-On)")}</h3>
           <%= if @oidc_env_configured do %>
             <p class="text-sm text-base-content/70 mb-4">
               {gettext("Some values are set via environment variables. Those fields are read-only.")}
@@ -853,6 +877,7 @@ defmodule MvWeb.GlobalSettingsLive do
         socket =
           socket
           |> assign(:settings, fresh_settings)
+          |> assign(:registration_enabled, fresh_settings.registration_enabled != false)
           |> assign(:vereinfacht_api_key_set, present?(fresh_settings.vereinfacht_api_key))
           |> assign(:oidc_client_secret_set, Mv.Config.oidc_client_secret_set?())
           |> assign(:oidc_configured, Mv.Config.oidc_configured?())
@@ -889,6 +914,24 @@ defmodule MvWeb.GlobalSettingsLive do
     {:noreply, persist_join_form_settings(socket)}
   end
 
+  @impl true
+  def handle_event("toggle_registration_enabled", _params, socket) do
+    settings = socket.assigns.settings
+    new_value = not socket.assigns.registration_enabled
+
+    case Membership.update_settings(settings, %{registration_enabled: new_value}) do
+      {:ok, updated_settings} ->
+        {:noreply,
+         socket
+         |> assign(:settings, updated_settings)
+         |> assign(:registration_enabled, updated_settings.registration_enabled != false)
+         |> assign_form()}
+
+      {:error, _} ->
+        {:noreply, put_flash(socket, :error, gettext("Failed to update setting."))}
+    end
+  end
+
   @impl true
   def handle_event("toggle_add_field_dropdown", _params, socket) do
     {:noreply,