Add login route with hardcoded password validation

lib/music_library_web/controllers/session_controller.ex

@@ -0,0 +1,21 @@
+defmodule MusicLibraryWeb.SessionController do
+  use MusicLibraryWeb, :controller
+
+  @empty_form %{"password" => ""}
+
+  def new(conn, _params) do
+    conn |> render(:new, form: @empty_form, layout: {MusicLibraryWeb.Layouts, "unauthenticated"})
+  end
+
+  def create(conn, params) do
+    password = params["password"]
+
+    if password == "password" do
+      redirect(conn, to: "/")
+    else
+      conn
+      |> put_flash(:error, "Invalid password")
+      |> redirect(to: ~p"/login")
+    end
+  end
+end