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.

database/migrations/2026_07_19_161117_create_sites_table.php

@@ -0,0 +1,35 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    /**
+     * Run the migrations.
+     */
+    public function up(): void
+    {
+        Schema::create('sites', function (Blueprint $table) {
+            $table->id();
+            $table->string('collection');
+            $table->string('domain');
+            $table->text('url')->nullable();
+            $table->string('title')->nullable();
+            $table->text('description')->nullable();
+            $table->text('keywords')->nullable();
+            $table->timestamps();
+
+            $table->unique(['collection', 'domain']);
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        Schema::dropIfExists('sites');
+    }
+};