User form: red warning for OIDC users when setting/changing password

- Show alert when user has oidc_id and password section is visible.
- Explains that password here does not change SSO/identity provider password.

lib/mv_web/live/user_live/form.ex

@@ -81,6 +81,18 @@ defmodule MvWeb.UserLive.Form do
 
           <%= if @show_password_fields do %>
             <div class="p-4 mt-4 space-y-4 rounded-lg bg-gray-50">
+              <%= if @user && MvWeb.Helpers.UserHelpers.has_oidc?(@user) do %>
+                <div class="p-3 mb-4 border border-red-300 rounded-lg bg-red-50" role="alert">
+                  <p class="text-sm font-semibold text-red-800">
+                    {gettext("SSO / OIDC user")}
+                  </p>
+                  <p class="mt-1 text-sm text-red-700">
+                    {gettext(
+                      "This user is linked via SSO (Single Sign-On). A password set or changed here only affects login with email and password in this application. It does not change the password in your identity provider (e.g. Authentik). To change the SSO password, use the identity provider or your organization's IT."
+                    )}
+                  </p>
+                </div>
+              <% end %>
               <.input
                 field={@form[:password]}
                 label={gettext("Password")}