Initial commit: Laravel scaffold + Common Crawl site indexing

Adds Site/SitePage models and the crawlindex:fetch command, which pulls
CDX index records from Common Crawl and optionally enriches them with
page title/description/keywords/body text extracted from the WARC
archive. CDX/WARC access and the site/page upsert logic live in
CommonCrawlIndexService and WarcRecordFetcher.

public/index.php

@@ -0,0 +1,20 @@
+<?php
+
+use Illuminate\Foundation\Application;
+use Illuminate\Http\Request;
+
+define('LARAVEL_START', microtime(true));
+
+// Determine if the application is in maintenance mode...
+if (file_exists($maintenance = __DIR__.'/../storage/framework/maintenance.php')) {
+    require $maintenance;
+}
+
+// Register the Composer autoloader...
+require __DIR__.'/../vendor/autoload.php';
+
+// Bootstrap Laravel and handle the request...
+/** @var Application $app */
+$app = require_once __DIR__.'/../bootstrap/app.php';
+
+$app->handleRequest(Request::capture());