fix: flush queued cookies between requests in LaravelHttpServer

[cyppe]

Problem

LaravelHttpServer serves every request of a browser test from one long-lived container. Cookies queued through Cookie::queue() land in the CookieJar singleton, and AddQueuedCookiesToResponse attaches every queued cookie to a response but never removes it from the jar. Nothing else does either:

• FPM discards the jar with the process;
• Octane flushes it between requests;
• the in-process test server keeps it for the whole test.

So a cookie queued by the first request is re-sent on every later response of the same test, including responses of routes that never queued anything.

Impact

A browser test cannot verify which response hands a cookie to the browser, and a cookie a page deliberately queues once (for example a first-party attribution cookie written on the first page after consent) shows up on every Livewire/XHR response afterwards. It also masks application bugs: code that forgets to queue a cookie on a later page still "works" in the test because the stale queue is replayed. We hit this while testing a consent-dependent cookie hand-over in a Laravel app: the assertion "exactly one response carried the cookie" saw five.

Fix

Flush the jar before handling each request, next to the existing forgetScopedInstances() (same per-request lifecycle FPM and Octane provide):

app()->make(CookieJar::class)->flushQueuedCookies();

Test

it does not re-send a cookie queued in an earlier request records the Set-Cookie headers of two requests through RequestHandled: the first route queues a cookie, the second does not. On the unfixed source the cookie appears on both responses (['queue-cookie', 'no-cookie']); with the fix only on the first.

Run: vendor/bin/pest tests/Unit/Drivers/Laravel/LaravelHttpServerTest.php (6 passed).