Let the admin choose one of eight colour profiles

Indigo (the default), Blue, Teal, Green, Amber, Rose and Violet in the
Vibrant style and Graphite in the Neutral style are generated from
config into the stylesheet. Admin settings opens with a colour profile
card: a swatch previews the profile on the page, and Save Settings
stores it as color_profile, which AppServiceProvider hands to the
package's resolver, so every page, mail and error page wears it. An
unknown profile is refused, and a saved one that disappears falls back
to indigo.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01V9NnLxnPp8vaaurb3Z1MFy

tests/Feature/Admin/AdminSettingsTest.php

@@ -128,3 +128,32 @@ test('admin can remove the logo through its dialog', function () {
     expect(Setting::get('site_logo'))->toBeNull();
     Storage::disk('public')->assertMissing($path);
 });
+
+test('admin chooses the colour profile, starting from the saved one', function () {
+    $admin = User::query()->where('is_admin', true)->first();
+
+    Livewire::actingAs($admin)
+        ->test(AdminSettings::class)
+        ->assertSet('colorProfile', 'indigo')
+        ->set('colorProfile', 'teal')
+        ->call('saveSettings')
+        ->assertHasNoErrors();
+
+    expect(Setting::get('color_profile'))->toBe('teal');
+
+    Livewire::actingAs($admin)
+        ->test(AdminSettings::class)
+        ->assertSet('colorProfile', 'teal');
+});
+
+test('a colour profile that was not generated is refused', function () {
+    $admin = User::query()->where('is_admin', true)->first();
+
+    Livewire::actingAs($admin)
+        ->test(AdminSettings::class)
+        ->set('colorProfile', 'ocean')
+        ->call('saveSettings')
+        ->assertHasErrors(['colorProfile' => 'in']);
+
+    expect(Setting::get('color_profile'))->toBeNull();
+});