Fill the FAB and icon-button glyphs, and cut small ones at 20

M3 asks a FAB's icon and a default (non-toggle) icon button's icon to be filled,
never outlined; the toggle half of that rule was already right, so only the
`$selected === null` case changed. Every glyph these components draw at 20px now
passes `optical="20"` for the cut M3 draws at that size — button xs/sm, group,
menu item, the alert, snackbar and FAB-menu close buttons, the stat's icon.
Plan step 18, actions.md ACT-14, ACT-15.

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

resources/views/components/stat.blade.php

@@ -17,7 +17,7 @@
 <div {{ $attributes->class('flex flex-col gap-1 rounded-corner-lg bg-surface-container p-4') }}>
     <div class="flex items-center gap-2 type-label-lg text-on-surface-variant">
         @if ($icon)
-            <x-livewire-material::icon :name="$icon" class="size-5" />
+            <x-livewire-material::icon :name="$icon" optical="20" class="size-5" />
         @endif
         <span>{{ $title }}</span>
     </div>