feat: implement variadic parameter handling in ReferenceHandler

- Add support for variadic parameters (...) in prepareArguments method
- Collect all numeric-indexed arguments starting from parameter position
- Add proper error handling for variadic parameter processing
- Remove TODO comment and complete the implementation
- Maintain backward compatibility with existing parameter handling

Fixes the TODO item in ReferenceHandler.php line 88 and enables
proper handling of functions with variadic parameters in MCP tools
and resources.

Author: monayemislam

src/Capability/Registry/ReferenceHandler.php

@@ -85,10 +85,28 @@ private function prepareArguments(\ReflectionFunctionAbstract $reflection, array
         $finalArgs = [];
 
         foreach ($reflection->getParameters() as $parameter) {
-            // TODO: Handle variadic parameters.
             $paramName = $parameter->getName();
             $paramPosition = $parameter->getPosition();
 
+            // Handle variadic parameters
+            if ($parameter->isVariadic()) {
+                // For variadic parameters, collect all remaining arguments
+                $variadicArgs = [];
+                foreach ($arguments as $key => $value) {
+                    if (is_numeric($key) && $key >= $paramPosition) {
+                        try {
+                            $variadicArgs[] = $this->castArgumentType($value, $parameter);
+                        } catch (InvalidArgumentException $e) {
+                            throw RegistryException::invalidParams($e->getMessage(), $e);
+                        } catch (\Throwable $e) {
+                            throw RegistryException::internalError("Error processing variadic parameter `{$paramName}`: {$e->getMessage()}", $e);
+                        }
+                    }
+                }
+                $finalArgs[$paramPosition] = $variadicArgs;
+                continue;
+            }
+
             if (isset($arguments[$paramName])) {
                 $argument = $arguments[$paramName];
                 try {