feat: extend GeminiProvider with social-media aspect ratios

The stock provider only exposes 1:1, 2:3, 3:2 via defaultImageOptions()
match statement — any other ratio gets silently dropped to null.

ExtendedGeminiProvider adds 9:16, 16:9, 4:3, 3:4, 4:5, 5:4, 21:9 so
Image::of()->size('9:16') now works for Reels/Stories/TikTok/Shorts
and size('16:9') for X/LinkedIn/YouTube landscape content.

Gemini's native API supports all these ratios; the SDK restriction was
purely in the provider's match statement.

app/Ai/Providers/ExtendedGeminiProvider.php

@@ -0,0 +1,46 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Ai\Providers;
+
+use Laravel\Ai\Providers\GeminiProvider;
+
+/**
+ * Extends the base Gemini provider with social-media-friendly aspect ratios.
+ *
+ * The stock provider only exposes 1:1, 2:3, 3:2. Social posts need 9:16
+ * (Reels/Stories/TikTok/Shorts) and 16:9 (X/LinkedIn/Facebook video).
+ * Gemini's native API supports both, but the SDK's match statement silently
+ * drops anything outside its three documented ratios. We re-expose them here.
+ */
+class ExtendedGeminiProvider extends GeminiProvider
+{
+    /**
+     * @param  'low'|'medium'|'high'|'1K'|'2K'|'4K'|null  $quality
+     */
+    public function defaultImageOptions(?string $size = null, $quality = null): array
+    {
+        return array_filter([
+            'image_size' => match ($quality) {
+                'low', '1K' => '1K',
+                'medium', '2K' => '2K',
+                'high', '4K' => '4K',
+                default => '1K',
+            },
+            'aspect_ratio' => match ($size) {
+                '1:1' => '1:1',
+                '2:3' => '2:3',
+                '3:2' => '3:2',
+                '9:16' => '9:16',
+                '16:9' => '16:9',
+                '4:3' => '4:3',
+                '3:4' => '3:4',
+                '4:5' => '4:5',
+                '5:4' => '5:4',
+                '21:9' => '21:9',
+                default => null,
+            },
+        ]);
+    }
+}

app/Providers/AppServiceProvider.php

@@ -4,6 +4,7 @@
 
 namespace App\Providers;
 
+use App\Ai\Providers\ExtendedGeminiProvider;
 use App\Listeners\StripeEventListener;
 use App\Models\Account;
 use App\Models\AiMessage;
@@ -32,6 +33,7 @@
 use Illuminate\Auth\Notifications\ResetPassword;
 use Illuminate\Auth\Notifications\VerifyEmail;
 use Illuminate\Cache\RateLimiting\Limit;
+use Illuminate\Contracts\Events\Dispatcher;
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\Relations\Relation;
 use Illuminate\Http\Request;
@@ -43,6 +45,8 @@
 use Illuminate\Support\Facades\RateLimiter;
 use Illuminate\Support\ServiceProvider;
 use Illuminate\Validation\Rules\Password;
+use Laravel\Ai\Ai;
+use Laravel\Ai\Gateway\Gemini\GeminiGateway;
 use Laravel\Cashier\Cashier;
 use Laravel\Cashier\Events\WebhookReceived;
 use Laravel\Nightwatch\Facades\Nightwatch;
@@ -85,6 +89,7 @@ public function boot(): void
     {
         $this->configureDefaults();
         $this->configureMorphMap();
+        $this->configureAi();
         $this->configurePostHog();
         $this->configureRateLimiting();
         $this->configureSocialite();
@@ -99,6 +104,17 @@ public function boot(): void
         Feature::discover();
     }
 
+    protected function configureAi(): void
+    {
+        Ai::extend('gemini', function (array $config) {
+            return new ExtendedGeminiProvider(
+                new GeminiGateway($this->app['events']),
+                $config,
+                $this->app->make(Dispatcher::class),
+            );
+        });
+    }
+
     protected function configureMorphMap(): void
     {
         Relation::enforceMorphMap([

tests/Unit/Ai/Providers/ExtendedGeminiProviderTest.php

@@ -0,0 +1,46 @@
+<?php
+
+declare(strict_types=1);
+
+use App\Ai\Providers\ExtendedGeminiProvider;
+use Illuminate\Contracts\Events\Dispatcher;
+use Laravel\Ai\Gateway\Gemini\GeminiGateway;
+
+beforeEach(function () {
+    $this->provider = new ExtendedGeminiProvider(
+        new GeminiGateway(app(Dispatcher::class)),
+        ['name' => 'gemini', 'driver' => 'gemini'],
+        app(Dispatcher::class),
+    );
+});
+
+test('supports social media vertical aspect ratio 9:16', function () {
+    $options = $this->provider->defaultImageOptions('9:16');
+
+    expect($options['aspect_ratio'])->toBe('9:16');
+});
+
+test('supports social media horizontal aspect ratio 16:9', function () {
+    $options = $this->provider->defaultImageOptions('16:9');
+
+    expect($options['aspect_ratio'])->toBe('16:9');
+});
+
+test('still supports the three original ratios from the base provider', function () {
+    expect($this->provider->defaultImageOptions('1:1')['aspect_ratio'])->toBe('1:1');
+    expect($this->provider->defaultImageOptions('2:3')['aspect_ratio'])->toBe('2:3');
+    expect($this->provider->defaultImageOptions('3:2')['aspect_ratio'])->toBe('3:2');
+});
+
+test('supports additional Instagram-friendly ratios', function () {
+    expect($this->provider->defaultImageOptions('4:5')['aspect_ratio'])->toBe('4:5');
+    expect($this->provider->defaultImageOptions('5:4')['aspect_ratio'])->toBe('5:4');
+    expect($this->provider->defaultImageOptions('4:3')['aspect_ratio'])->toBe('4:3');
+    expect($this->provider->defaultImageOptions('3:4')['aspect_ratio'])->toBe('3:4');
+});
+
+test('drops unsupported aspect ratios silently', function () {
+    $options = $this->provider->defaultImageOptions('gibberish');
+
+    expect($options)->not->toHaveKey('aspect_ratio');
+});