Add a patch() route helper to RouteBuilder #653

Problem

Quantum\Router\RouteBuilder has route helpers for get(), post(), put() and delete(), but none for patch(). PATCH is a supported method everywhere else: Request::METHODS, HttpClient::METHODS, Csrf::METHODS, and the request body parsing treats it like PUT and POST. A PATCH route can only be written with add($path, 'PATCH', $handler).

Proposal

Add RouteBuilder::patch(string $path, $handler, string $action = null): self in src/Router/RouteBuilder.php, next to put(), written the same way:

return $this->addRoute(['PATCH'], $path, $handler, $action);

It only adds a method, so nothing existing changes. Routes declared with add($path, 'PATCH', ...) keep working.

Acceptance

• patch() registers a route with the PATCH method, with a handler and with a controller action, the same as the other helpers.
• A unit test in tests/Unit/Router/ next to the tests of put() and delete().
• CHANGELOG.md entry under Added.
• Docs: the routing page lists patch() with the other verb helpers (separate docs ticket).