feat: add screens endpoint

* according to https://docs.usetrmnl.com/go/diy/byos#screens

routes/api.php

@@ -276,6 +276,34 @@ Route::post('/display/update', function (Request $request) {
     ->name('display.update')
     ->middleware('auth:sanctum', 'ability:update-screen');
 
+Route::post('/screens', function (Request $request) {
+    $mac_address = $request->header('id');
+    $access_token = $request->header('access-token');
+    $device = Device::where('mac_address', $mac_address)
+        ->where('api_key', $access_token)
+        ->first();
+
+    if (! $device) {
+        return response()->json([
+            'message' => 'MAC Address not registered or invalid access token',
+        ], 404);
+    }
+
+    $request->validate([
+        'image' => 'array|required',
+        'image.content' => 'string|required',
+        'image.file_name' => 'string',
+    ]);
+    $content = $request['image']['content'];
+
+    $view = Blade::render($content);
+    GenerateScreenJob::dispatchSync($device->id, null, $view);
+
+    return response()->json([
+        'message' => 'success',
+    ]);
+})->name('screens.update');
+
 Route::get('/display/status', function (Request $request) {
     $request->validate([
         'device_id' => 'required|exists:devices,id',

tests/Feature/Api/DeviceEndpointsTest.php

@@ -1,5 +1,6 @@
 <?php
 
+use App\Jobs\GenerateScreenJob;
 use App\Models\Device;
 use App\Models\Playlist;
 use App\Models\PlaylistItem;
@@ -838,3 +839,42 @@ test('device returns sleep.png and correct refresh time when paused', function (
     expect($json['image_url'])->toContain('sleep.png');
     expect($json['refresh_rate'])->toBeLessThanOrEqual(3600); // ~60 min
 });
+
+test('screens endpoint accepts nullable file_name', function () {
+    Queue::fake();
+
+    $device = Device::factory()->create([
+        'mac_address' => '00:11:22:33:44:55',
+        'api_key' => 'test-api-key',
+    ]);
+
+    $response = $this->withHeaders([
+        'id' => $device->mac_address,
+        'access-token' => $device->api_key,
+    ])->post('/api/screens', [
+        'image' => [
+            'content' => '<div>Test content</div>',
+        ],
+    ]);
+
+    $response->assertOk();
+
+    Queue::assertPushed(GenerateScreenJob::class);
+});
+
+test('screens endpoint returns 404 for invalid device credentials', function () {
+    $response = $this->withHeaders([
+        'id' => 'invalid-mac',
+        'access-token' => 'invalid-key',
+    ])->post('/api/screens', [
+        'image' => [
+            'content' => '<div>Test content</div>',
+            'file_name' => 'test.blade.php',
+        ],
+    ]);
+
+    $response->assertNotFound()
+        ->assertJson([
+            'message' => 'MAC Address not registered or invalid access token',
+        ]);
+});