Initial commit — Parker County Slingshot Rentals booking site

Full booking system with Square card-on-file, 10-step booking flow,
pre-departure checklist, and Mailjet email integration.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,11 @@
+# Credentials (server-only — never commit real values)
+db.php
+config.php
+
+# Uploads / user files
+uploads/
+*.log
+
+# OS / editor
+.DS_Store
+*.swp