Week 1 infrastructure: Docker environments, deploy pipeline, bookstore-core scaffold

Docker Compose environments for dev/staging/production (MariaDB, Redis,
Caddy, Action Scheduler cron sidecar), an idempotent deploy script,
git-hook-based deploy pipeline, backup/restore scripts, and the
bookstore-core plugin stub with WooCommerce HPOS compatibility declared.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

docker/caddy/Caddyfile.production

@@ -0,0 +1,22 @@
+{$SITE_DOMAIN} {
+	encode gzip
+
+	root * /var/www/html
+
+	@no_cache path /cart* /checkout* /my-account* /wp-admin* /wp-login.php
+	header @no_cache Cache-Control "no-store, no-cache, must-revalidate"
+
+	request_body {
+		max_size 32MB
+	}
+
+	php_fastcgi wordpress:9000
+	file_server
+
+	log {
+		output file /data/access.log {
+			roll_size 50MiB
+			roll_keep 10
+		}
+	}
+}