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.

.gitignore

@@ -0,0 +1,27 @@
+*.log
+.DS_Store
+.env
+.env.backup
+.env.production
+.phpactor.json
+.phpunit.result.cache
+/.codex
+/.cursor/
+/.idea
+/.nova
+/.phpunit.cache
+/.vscode
+/.zed
+/auth.json
+/node_modules
+/public/build
+/public/fonts-manifest.dev.json
+/public/hot
+/public/storage
+/storage/*.key
+/storage/pail
+/vendor
+_ide_helper.php
+Homestead.json
+Homestead.yaml
+Thumbs.db