Fix Model class instantiation for proper platform support

- Add createModelForPlatform method to create appropriate model classes
- Support OpenAI, Anthropic, Google, Ollama, and Mistral platforms
- Use specific model classes instead of generic Model for proper capability detection
- Fallback to generic Model for unknown platforms
- This resolves the ModelClient registration error

Author: OskarStark

src/ai-bundle/src/Command/PlatformInvokeCommand.php

@@ -105,7 +105,7 @@ protected function initialize(InputInterface $input, OutputInterface $output): v
             throw new InvalidArgumentException('Model is required.');
         }
 
-        $this->model = new Model($modelName);
+        $this->model = $this->createModelForPlatform($platformName, $modelName);
 
         $this->message = trim((string) $input->getArgument('message'));
 
@@ -148,4 +148,16 @@ protected function execute(InputInterface $input, OutputInterface $output): int
         return Command::SUCCESS;
     }
 
+    private function createModelForPlatform(string $platformName, string $modelName): Model
+    {
+        return match ($platformName) {
+            'openai' => new \Symfony\AI\Platform\Bridge\OpenAi\Gpt($modelName),
+            'anthropic' => new \Symfony\AI\Platform\Bridge\Anthropic\Claude($modelName),
+            'google' => new \Symfony\AI\Platform\Bridge\Gemini\Gemini($modelName),
+            'ollama' => new \Symfony\AI\Platform\Bridge\Ollama\Ollama($modelName),
+            'mistral' => new \Symfony\AI\Platform\Bridge\Mistral\Mistral($modelName),
+            default => new Model($modelName), // Fallback to generic model
+        };
+    }
+
 }