[Agent] Simplify Platform tool by using asText() method

Removed explicit await() and result type matching by using the
ResultPromise::asText() convenience method which handles the
await internally and extracts text content directly.

Author: OskarStark

src/agent/src/Toolbox/Tool/Platform.php

@@ -12,9 +12,6 @@
 namespace Symfony\AI\Agent\Toolbox\Tool;
 
 use Symfony\AI\Platform\PlatformInterface;
-use Symfony\AI\Platform\Result\AudioResult;
-use Symfony\AI\Platform\Result\ImageResult;
-use Symfony\AI\Platform\Result\TextResult;
 
 /**
  * Wraps a Platform instance as a tool, allowing agents to use specialized platforms for specific tasks.
@@ -41,17 +38,10 @@ public function __construct(
      */
     public function __invoke(array|string|object $input): string
     {
-        $result = $this->platform->invoke(
+        return $this->platform->invoke(
             $this->model,
             $input,
             $this->options,
-        )->await();
-
-        return match (true) {
-            $result instanceof TextResult => $result->getContent(),
-            $result instanceof AudioResult => $result->getText() ?? base64_encode($result->getAudio()),
-            $result instanceof ImageResult => $result->getText() ?? base64_encode($result->getImage()),
-            default => throw new \LogicException(\sprintf('Unsupported result type "%s".', $result::class)),
-        };
+        )->asText();
     }
 }