feat: headless server mode with ExRatatui SSH daemon (issue #26, phase 1)

lib/bds/tui.ex

@@ -0,0 +1,38 @@
+defmodule BDS.TUI do
+  @moduledoc """
+  Terminal UI entry point (issue #26), served per SSH connection by
+  `ExRatatui.SSH.Daemon` in server mode and runnable locally.
+
+  Placeholder shell for now: renders the app banner while the workbench
+  renderer lands in a later phase. The UI locale is the server-side UI
+  language setting, same as the GUI.
+  """
+
+  use ExRatatui.App
+  use Gettext, backend: BDS.Gettext
+
+  alias BDS.Desktop.UILocale
+  alias ExRatatui.Layout.Rect
+  alias ExRatatui.Widgets.Paragraph
+
+  @impl true
+  def mount(_opts) do
+    UILocale.put(BDS.Desktop.ShellData.ui_language())
+    {:ok, %{}}
+  end
+
+  @impl true
+  def render(_state, frame) do
+    text =
+      "bDS2 — " <>
+        dgettext("ui", "Blogging Desktop Server") <>
+        "\n\n" <>
+        dgettext("ui", "Press q to quit.")
+
+    [{%Paragraph{text: text}, %Rect{x: 0, y: 0, width: frame.width, height: frame.height}}]
+  end
+
+  @impl true
+  def handle_event(%ExRatatui.Event.Key{code: "q"}, state), do: {:stop, state}
+  def handle_event(_event, state), do: {:noreply, state}
+end