Implement stream_cast in StreamWrapper

This allows PHP to extract native file descriptors when passing user-space
streams to low-level functions like proc_open(). This resolves compatibility
issues with Symfony Process and Laravel's artisan serve command.

Author: rcalicdan

src/Command/RunCommand.php

@@ -64,4 +64,4 @@ public function execute(array $args, $outputStream = STDOUT, $errorStream = STDE
 
         return 0;
     }
-}
+}

src/Internal/StreamWrapper.php

@@ -278,6 +278,16 @@ public function stream_stat(): array|false
         return fstat($this->handle);
     }
 
+    /**
+     * Extracts the underlying native file descriptor for C-level functions like proc_open() or stream_select().
+     *
+     * @return resource|false
+     */
+    public function stream_cast(int $cast_as)
+    {
+        return $this->handle !== null ? $this->handle : false;
+    }
+
     public function stream_seek(int $offset, int $whence = SEEK_SET): bool
     {
         if ($this->handle === null) {

src/Internal/StreamWrapperInterface.php

@@ -58,4 +58,9 @@ public function unlink(string $path): bool;
     public function rename(string $pathFrom, string $pathTo): bool;
 
     public function stream_metadata(string $path, int $option, mixed $value): bool;
+
+    /**
+     * @return resource|false
+     */
+    public function stream_cast(int $cast_as);
 }