Add Laravel AI SDK tool format support

[pushpak1300]

Relay currently only returns Prism Tool objects, making it compatible with apps built on the Laravel AI SDK. This adds a ToolFormat::AI_SDK option so Relay::tools() can return Laravel\Ai\Contracts\Tool\ instances.

Usage

// Globally via config or env var (RELAY_TOOL_FORMAT=aisdk)
'tool_format' => ToolFormat::AI_SDK,

// Per-call override
$tools = Relay::make('puppeteer')->format(ToolFormat::AI_SDK)->tools();

Breaking Changes

PHP 8.4 and Laravel 12 are now required (previously PHP 8.2+ / Laravel 11+).

The laravel/ai package, a first-party Laravel package included in Laravel 12, requires PHP 8.4. This PR promotes laravel/ai as a hard dependency, providing the Tool contract and illuminate/json-schema types used in its type signatures. Therefore, Relay’s minimum requirements must align with it. Supporting Laravel 11 or PHP < 8.4 with a hard laravel/ai dependency is complex and not feasible.

[pushpak1300]

Once you configure Relay to return aisdk format tools, you can pass them directly into any Laravel AI agent's tools() method.

1. Configure the tool format

Either globally via config/relay.php (or the RELAY_TOOL_FORMAT=aisdk env var):

'tool_format' => ToolFormat::AI_SDK,

Or per-call:

$tools = Relay::make('puppeteer')->format(ToolFormat::AI_SDK)->tools();

2. Use the tools in an agent

use Laravel\Ai\Agent;
use Laravel\Ai\Contracts\Tool;
use Prism\Relay\Facades\Relay;
use Prism\Relay\Enums\ToolFormat;

class BrowserAgent extends Agent
{
    /**
     * Get the tools available to the agent.
     *
     * @return Tool[]
     */
    public function tools(): iterable
    {
        return Relay::make('puppeteer')
            ->format(ToolFormat::AI_SDK)
            ->tools();
    }
}

This lets you expose any MCP server's tools to a Laravel AI agent without writing any Tool implementations by hand — Relay introspects the MCP server's schema and generates compliant Laravel\Ai\Contracts\Tool instances automatically.

Mixing Relay tools with hand-written tools

Since tools() returns an iterable, you can spread Relay tools alongside your own:

public function tools(): iterable
{
    return [
        new RandomNumberGenerator,
        ...Relay::make('puppeteer')->format(ToolFormat::AI_SDK)->tools(),
    ];
}