feat: allow disabling registration

lib/mv_web/live/auth/sign_in_live.ex

@@ -19,7 +19,7 @@ defmodule MvWeb.SignInLive do
 
   alias AshAuthentication.Phoenix.Components
   alias Mv.Config
-  alias MvWeb.{AuthOverridesDE, Layouts}
+  alias MvWeb.{AuthOverridesDE, AuthOverridesRegistrationDisabled, Layouts}
 
   @impl true
   def mount(_params, session, socket) do
@@ -36,7 +36,18 @@ defmodule MvWeb.SignInLive do
     # without _gettext support (e.g. HorizontalRule) still render in German.
     base_overrides = Map.get(session, "overrides", [AshAuthentication.Phoenix.Overrides.Default])
     locale_overrides = if locale == "de", do: [AuthOverridesDE], else: []
-    overrides = locale_overrides ++ base_overrides
+
+    registration_disabled =
+      if session["registration_enabled"] == false,
+        do: [AuthOverridesRegistrationDisabled],
+        else: []
+
+    # When registration is disabled: hide register link (register_path: nil) and hide
+    # "Need an account?" toggle (override register_toggle_text: nil so it takes precedence).
+    overrides = registration_disabled ++ locale_overrides ++ base_overrides
+
+    register_path =
+      if session["registration_enabled"] == false, do: nil, else: session["register_path"]
 
     socket =
       socket
@@ -44,7 +55,7 @@ defmodule MvWeb.SignInLive do
       |> assign_new(:otp_app, fn -> nil end)
       |> assign(:path, session["path"] || "/")
       |> assign(:reset_path, session["reset_path"])
-      |> assign(:register_path, session["register_path"])
+      |> assign(:register_path, register_path)
       |> assign(:current_tenant, session["tenant"])
       |> assign(:resources, session["resources"])
       |> assign(:context, session["context"] || %{})