Let a docked toolbar carry a FAB

Plan step 25 (navigation Missing): M3's toolbar configuration table lists
"With FAB" for both toolbars, but the `fab` slot was gated to the floating one.
A docked toolbar now takes it at its end, inside the toolbar where the arrow
keys reach it; its controls gather at the start, and the FAB rests flat on the
bar — elevation 0 for a FAB nested in another component, as Compose's
bottomAppBarFabElevation is.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Qwx5USif3wFFmxtHg5U1g9

resources/views/components/toolbar.blade.php

@@ -4,8 +4,12 @@
      `vertical` stands it on end) or `docked` (a full-width bar in surface-container, for the bottom
      of a screen). `place` puts it over the page: `bottom` (centred above the bottom edge; a docked
      toolbar spans it) or `end` (centred against the end edge, for a vertical one); without it the
-     toolbar sits where it is written. A `fab` slot sets an `<x-fab>` beside a floating toolbar.
-     `label` names it for screen readers.
+     toolbar sits where it is written. A `fab` slot sets an `<x-fab>` beside a floating toolbar,
+     and at the end of a docked one — M3's "With FAB" configuration for both. On a docked toolbar the
+     controls then gather at the start and the FAB rests on the bar, flat: M3 gives a FAB nested in
+     another component elevation 0 (Compose's bottomAppBarFabElevation is 0 at every state), where
+     one beside a floating toolbar keeps its own. It is one of the toolbar's controls then, so the
+     arrow keys reach it. `label` names it for screen readers.
 
      A docked toolbar and a navigation bar occupy the same region of the screen and M3 says never to
      show both at once: the bar belongs on a primary page, the toolbar on a secondary or contextual
@@ -29,6 +33,7 @@
     $vertical = $vertical && $variant === 'floating';
     $place = in_array($place, ['bottom', 'end'], true) ? $place : null;
     $grouped = isset($fab) && $variant === 'floating';
+    $docksFab = isset($fab) && $variant === 'docked';
 @endphp
 
 @if ($grouped)
@@ -48,6 +53,10 @@
     {{ $attributes }}
 >
     {{ $slot }}
+
+    @if ($docksFab)
+        <div data-toolbar-fab>{{ $fab }}</div>
+    @endif
 </div>
 
 @if ($grouped)