Refactor Loop class to use a LoopTools singleton for tool management for Octane compatibility

[fsmonter]

Fixes #26

There is an Octane compatibility issue where registered tools don't persist between request cycles due to scoped instance recreation of the Loop class.

The proposed fix is storing the tools in a singleton LoopTools. Another option is making the Loop class a singleton but keep in mind the instance would be shared between users in Octane.

Current Behavior

// In LoopServiceProvider
$this->app->scoped(Loop::class, function ($app) {
    $loop = new Loop;
    $loop->setup();
    return $loop;
});

// In user's AppServiceProvider::boot()
Loop::toolkit(Kirschbaum\Loop\Filament\FilamentToolkit::make());

The Issue

1. Octane flushes scoped instances on every request lifecycle
2. Toolkits are registered in boot() which only run once when worker starts
3. Subsequent requests get fresh Loop instances without any registered toolkits
4. Users must implement a workaround in their applications

Current Application Workaround

// Users must add this to their AppServiceProvider::register()
$this->app->resolving('loop', function ($loop, $app) {
    $loop->toolkit(new MyToolkit());
});