feat(auth): improve OAuth buttons and OIDC settings layout

Add provider icons and full-width centered login buttons, organize OIDC fields, and remove hardcoded user IDs from the seeder.

tests/Feature/LoginPageBrandingTest.php

@@ -37,6 +37,28 @@ test('auth pages use the Coollabs purple background glow', function () {
         ->not->toMatch('/\.auth-shell\s*\{[^}]*color-mix\(in oklab, var\(--color-accent\) 9%, transparent\)/s');
 });
 
+test('external login providers are centered and full width', function () {
+    $login = file_get_contents(resource_path('views/auth/login.blade.php'));
+
+    expect($login)
+        ->toContain('class="flex flex-col gap-2"')
+        ->toContain('class="w-full justify-center"')
+        ->not->toContain('sm:w-[calc(50%-0.25rem)]');
+});
+
+test('external login providers display their icons except oidc', function () {
+    $login = file_get_contents(resource_path('views/auth/login.blade.php'));
+
+    expect($login)
+        ->toContain("@if (\$provider_setting->provider !== 'oidc')")
+        ->toContain("asset('svgs/'.\$provider_setting->provider.'.svg')")
+        ->toContain('class="size-5 shrink-0 dark:invert"');
+
+    foreach (['authentik', 'azure', 'bitbucket', 'clerk', 'discord', 'github', 'gitlab', 'google', 'infomaniak', 'zitadel'] as $provider) {
+        expect(public_path("svgs/{$provider}.svg"))->toBeFile();
+    }
+});
+
 test('error pages use the Coollabs purple background glow', function () {
     $styles = file_get_contents(resource_path('css/app.css'));
 

tests/Feature/SettingsOauthTest.php

@@ -94,6 +94,27 @@ it('shows oidc fields with a naked okta issuer url example', function () {
         ->assertDontSee('/oauth2/default', false);
 });
 
+it('groups oidc fields in the expected desktop order', function () {
+    $view = file_get_contents(resource_path('views/livewire/settings-oauth.blade.php'));
+    $fields = [
+        'redirect_uri',
+        'base_url',
+        'client_id',
+        'client_secret',
+        'scopes',
+        'clock_skew_seconds',
+        'custom_label',
+    ];
+    $positions = array_map(
+        fn (string $field): int|false => strpos($view, "id=\"oauth_settings_map.{{ \$provider }}.$field\""),
+        $fields,
+    );
+
+    expect($positions)->not->toContain(false)
+        ->and($positions)->toBe(collect($positions)->sort()->values()->all())
+        ->and($view)->toContain('<div class="lg:col-span-2">');
+});
+
 it('shows provider enable controls as settings section actions', function () {
     actingAsInstanceAdmin();
 

tests/Feature/UserSeederTest.php

@@ -0,0 +1,16 @@
+<?php
+
+use App\Models\User;
+use Database\Seeders\UserSeeder;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+
+uses(RefreshDatabase::class);
+
+it('leaves the user id sequence ready for new development users', function () {
+    $this->seed(UserSeeder::class);
+
+    $user = User::factory()->create();
+
+    expect(User::query()->orderBy('id')->pluck('id')->all())->toBe([0, 1, 2, 3])
+        ->and($user->id)->toBe(3);
+});