feat: switch to phoenix liveview

Co-authored-by: Copilot <copilot@github.com>

test/bds/desktop/shell_live_test.exs

@@ -0,0 +1,42 @@
+defmodule BDS.Desktop.ShellLiveTest do
+  use ExUnit.Case, async: false
+
+  import Phoenix.ConnTest
+  import Phoenix.LiveViewTest
+
+  @endpoint BDS.Desktop.Endpoint
+
+  test "shell live owns pane visibility and activity selection on the server" do
+    {:ok, view, html} = live_isolated(build_conn(), BDS.Desktop.ShellLive)
+
+    assert html =~ ~s(data-testid="sidebar-shell")
+    assert html =~ ~s(class="panel-shell is-hidden")
+    assert html =~ ~s(data-testid="activity-button")
+    assert html =~ ~s(data-view="posts")
+    assert html =~ ~s(data-view="media")
+    assert html =~ ~s(aria-label="Posts")
+
+    html =
+      view
+      |> element("[data-testid='toggle-sidebar']")
+      |> render_click()
+
+    assert html =~ ~s(class="sidebar-shell is-hidden")
+
+    html =
+      view
+      |> element("[data-testid='toggle-panel']")
+      |> render_click()
+
+    assert html =~ ~s(data-region="panel")
+    refute html =~ ~s(class="panel-shell is-hidden")
+
+    html =
+      view
+      |> element("[data-testid='activity-button'][data-view='media']")
+      |> render_click()
+
+    assert html =~ ~s(aria-label="Media")
+    assert html =~ ~s(data-view="media")
+  end
+end