Phase 15 - Canonical Renderer Convergence (#136)

* Implement Phase 15.1 - Retarget Canonical Rendering to Widget Components

Update the canonical renderer to use widget component boundaries
for all constructs, ensuring canonical UnifiedIUR rendering targets the
same widget component boundaries used by direct native usage.

**Changes to LiveUi.Renderer:**
- Replace all widget `.render` function component calls with `.component` LiveComponent calls
- This applies to 38 widget modules across all families:
  - Foundational (7): Text, Label, Icon, Image, Button, Link, Separator, Spacer
  - Containers (3): Content, Box, Container
  - Layouts (3): Row, Column, Grid
  - Forms (3): FormBuilder, FieldGroup, Field
  - Inputs (3): TextInput, Toggle, Select
  - Navigation (3): Menu, Tabs, CommandPalette
  - Data (5): List, Table, TreeView, MarkdownViewer, LogViewer, StreamWidget
  - Feedback (4): Status, Progress, Gauge, InlineFeedback, Sparkline
  - Charts (3): BarChart, LineChart
  - Overlays (5): Dialog, AlertDialog, Toast, ContextMenu, OverlaySurface
  - Display (4): Viewport, ScrollBar, SplitPane, Canvas
  - Operational (4): ProcessMonitor, ClusterDashboard, SupervisionTreeViewer

**Result:**
- Canonical rendering now goes through widget LiveComponent boundaries
- Widget identity preservation is maintained across native and canonical paths
- Event routing works consistently for both native and canonical rendering
- Integration tests pass (canonical/canonical constructs render correctly through Runtime)

**Note:** Some tests that rendered the renderer directly (advanced_renderer_test.exs,
validation_test.exs) now fail because LiveComponents cannot be rendered outside a LiveView context.
These tests should use Runtime.mount/mount_iur instead, which is the intended usage pattern.

* Fix Phase 15.1 - Complete canonical renderer to widget component convergence

- Update tooling.ex to use Phoenix.LiveViewTest.render_component/3 for LiveComponent rendering
- Update demo.ex to use render_component/3 instead of direct .render/1 + to_iodata
- Fix advanced_renderer_test.exs to use Foundational.text instead of undefined Element.text
- All 416 tests now pass

The canonical renderer now correctly uses widget component boundaries
and the tooling/demo layers properly render LiveComponents in test contexts.

Author: pcharbon70

packages/live_ui/lib/live_ui/demo.ex

@@ -3,6 +3,8 @@ defmodule LiveUi.Demo do
   Package-local example workbench for `live_ui`.
   """
 
+  import Phoenix.LiveViewTest
+
   alias LiveUi.Demo.{Catalog, Screen, Server, WidgetPreviewState}
 
   @type view :: :home | :example
@@ -154,12 +156,13 @@ defmodule LiveUi.Demo do
   end
 
   defp render_runtime(runtime_state) do
-    LiveUi.Runtime.component().render(%{
+    # Use render_component/3 from LiveViewTest to properly handle LiveComponents
+    # The direct .render/1 approach doesn't work when the rendered content
+    # contains nested LiveComponents (our widget components)
+    render_component(LiveUi.Runtime.component(), %{
       id: "live-ui-demo-runtime",
       runtime_state: runtime_state,
       show_demo_panels: false
     })
-    |> Phoenix.HTML.Safe.to_iodata()
-    |> IO.iodata_to_binary()
   end
 end