Reach M3's 48px target from every 40px navigation control

The theme toggle and the account-menu avatar are drawn 40px and had no target
extension; both now carry `touch-target`, and the avatar's clipping moves from
the button (which would have cut the pseudo-target off) to the <img>. The rail's
hand-rolled `after:` target becomes the same utility.
Plan: docs/plans/material-3-alignment.md, step 14 (navigation N-01).

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

resources/views/components/theme-toggle.blade.php

@@ -93,7 +93,7 @@
             x-bind:aria-pressed="($store.theme.resolved === 'dark').toString()"
             x-on:click="$store.theme.toggle()"
         @endif
-        {{ $attributes->class(['state-layer focus-ring inline-flex size-10 shrink-0 cursor-pointer items-center justify-center rounded-corner-full text-on-surface-variant transition-[border-radius] duration-(--md-sys-motion-spatial-fast-duration) ease-spatial-fast active:rounded-corner-sm']) }}
+        {{ $attributes->class(['state-layer touch-target focus-ring inline-flex size-10 shrink-0 cursor-pointer items-center justify-center rounded-corner-full text-on-surface-variant transition-[border-radius] duration-(--md-sys-motion-spatial-fast-duration) ease-spatial-fast active:rounded-corner-sm']) }}
     >
         @if ($mode === 'cycle')
             <x-livewire-material::icon name="light_mode" x-cloak x-show="$store.theme.choice === 'light'" />