Introduce UploadedFile class bridge implementation with tests.

src/adapter/ServerRequestAdapter.php

@@ -313,7 +313,7 @@ public function getServerParams(): array
      *
      * @return array Uploaded files from the PSR-7 ServerRequestInterface.
      *
-     * @phpstan-return array<mixed, mixed>
+     * @phpstan-return array<array-key, mixed>
      *
      * Usage example:
      * ```php

src/http/Request.php

@@ -7,7 +7,7 @@
 use Psr\Http\Message\{ServerRequestInterface, UploadedFileInterface};
 use Yii;
 use yii\base\InvalidConfigException;
-use yii\web\{CookieCollection, HeaderCollection, NotFoundHttpException, UploadedFile};
+use yii\web\{CookieCollection, HeaderCollection, NotFoundHttpException};
 use yii2\extensions\psrbridge\adapter\ServerRequestAdapter;
 use yii2\extensions\psrbridge\exception\Message;
 
@@ -777,8 +777,7 @@ public function resolve(): array
      * This method injects a stateless application start time header (`statelessAppStartTime`) into the request for
      * tracing and debugging purposes.
      *
-     * Once set, all request operations will use the PSR-7 ServerRequestInterface via the adapter until {@see reset()}
-     * is called.
+     * Once set, all request operations will use the PSR-7 ServerRequestInterface via the adapter until is called.
      *
      * @param ServerRequestInterface $request PSR-7 ServerRequestInterface instance to bridge.
      *
@@ -793,6 +792,8 @@ public function setPsr7Request(ServerRequestInterface $request): void
         $this->adapter = new ServerRequestAdapter(
             $request->withHeader('statelessAppStartTime', (string) microtime(true)),
         );
+
+        UploadedFile::setPsr7Adapter($this->adapter);
     }
 
     /**
@@ -851,6 +852,7 @@ private function createUploadedFile(UploadedFileInterface $psrFile): UploadedFil
                 'size' => $psrFile->getSize(),
                 'tempName' => $psrFile->getStream()->getMetadata('uri') ?? '',
                 'type' => $psrFile->getClientMediaType() ?? '',
+                'tempResource' => $psrFile->getStream()->detach(),
             ],
         );
     }

src/http/StatelessApplication.php

@@ -9,7 +9,7 @@
 use Throwable;
 use yii\base\{Event, InvalidConfigException};
 use yii\di\{Container, NotInstantiableException};
-use yii\web\{Application, UploadedFile};
+use yii\web\Application;
 
 use function array_merge;
 use function array_reverse;
@@ -387,7 +387,7 @@
      * Resets the StatelessApplication state and prepares the Yii2 environment for handling a PSR-7 request.
      *
      * Performs a full reinitialization of the application state, including event tracking, error handler cleanup,
-     * request adapter reset, session management, and PSR-7 request injection.
+     * request adapter reset, session management, uploaded file state reset, and PSR-7 request injection.
      *
      * This method ensures that the application is ready to process a new stateless request in worker or SAPI
      * environments, maintaining strict type safety and compatibility with Yii2 core components.
@@ -402,6 +402,9 @@
     {
         $this->startEventTracking();
 
+        // reset UploadedFile static state to avoid cross-request contamination
+        UploadedFile::reset();
+
         // parent constructor is called because StatelessApplication uses a custom initialization pattern
         // @phpstan-ignore-next-line
         parent::__construct($this->config);
@@ -441,7 +444,7 @@
     /**
      * Finalizes the application lifecycle and converts the Yii2 Response to a PSR-7 ResponseInterface.
      *
-     * Cleans up registered events, resets uploaded files, flushes the logger.
+     * Cleans up registered events, and flushes the logger.
      *
      * This method ensures that all application resources are released and the response is converted to a PSR-7
      * ResponseInterface for interoperability with PSR-7 compatible HTTP stacks.
@@ -457,10 +460,8 @@
     {
         $this->cleanupEvents();
 
-        UploadedFile::reset();
-
         if ($this->flushLogger) {
             $this->getLog()->getLogger()->flush(true);
         }
 
         return $response->getPsr7Response();
@@ -482,17 +483,17 @@
      */
     private function cleanupEvents(): void
     {
         Event::off('*', '*', $this->eventHandler);
 
         foreach (array_reverse($this->registeredEvents) as $event) {
             if ($event->sender !== null && method_exists($event->sender, 'off')) {
                 $event->sender->off($event->name);
             }
         }
 
         $this->registeredEvents = [];
 
         Event::offAll();
     }
 
     /**
@@ -512,7 +513,7 @@
     {
         $response = $this->errorHandler->handleException($exception);
 
         $this->trigger(self::EVENT_AFTER_REQUEST);
 
         $this->state = self::STATE_END;
 
@@ -547,6 +548,6 @@
      */
     private function startEventTracking(): void
     {
         Event::on('*', '*', $this->eventHandler);
     }
 }