Let a rail hide when collapsed instead of narrowing

Plan step 25 (navigation Missing): M3's "Expanded behavior | Hide when
collapsed" was only implicit below `medium` in the adaptive rail.
`<x-navigation-rail hide-when-collapsed>` (collapsible and adaptive rails) takes
the rail out of the layout when it is collapsed; `$store.rail.show()` from an
app-bar menu button brings it back expanded over a scrim, sliding in, and its
own menu button docks it again. It does not reach the bands where the window,
not the visitor, collapses a rail (below `medium` for collapsible, `medium` for
adaptive), since M3's collapsed rail may never hide. Every `rail-collapsed`
branch now stops while the rail is open. `<x-app-shell hide-rail-when-collapsed>`
exposes it.

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

resources/views/components/app-shell.blade.php

@@ -56,7 +56,11 @@
      phone opens. `label` names both navigation landmarks ("Main"); `rail-width` is the expanded
      rail's width; `tall-bar` picks M3's 80px navigation bar over the 64px one, and the bottom
      offset every pinned thing reads follows it; `hide-bar-on-scroll` lets the bar leave the window
-     while the page scrolls down, and `--material-bottom-bar` goes down and comes back with it.
+     while the page scrolls down, and `--material-bottom-bar` goes down and comes back with it;
+     `hide-rail-when-collapsed` is M3's immersive configuration — from `expanded` the rail leaves
+     the layout when the menu button collapses it, rather than narrowing to 96px, so the page has
+     the whole window. The only way back is `$store.rail.show()`, so put a menu button in the app
+     bar at every width, not just below `medium`.
 
      `banner` or `top` is a decision about what the bar belongs to: an application-wide bar — one
      search, one account menu, the same on every page — spans the window and the rail starts under
@@ -86,6 +90,7 @@
     'railWidth' => '16rem',
     'tallBar' => false,
     'hideBarOnScroll' => false,
+    'hideRailWhenCollapsed' => false,
 ])
 
 @php
@@ -132,7 +137,7 @@
     @endisset
 
     <div class="flex-1 medium:flex">
-        <x-livewire-material::navigation-rail mode="adaptive" :label="$label" :width="$railWidth">
+        <x-livewire-material::navigation-rail mode="adaptive" :label="$label" :width="$railWidth" :hide-when-collapsed="$hideRailWhenCollapsed">
             @isset($brand)
                 <x-slot:brand>{{ $brand }}</x-slot:brand>
             @endisset