feat: Add Supabase configuration and migrations for MC Cars application

- Create Kong declarative configuration for routing and authentication.
- Implement initialization script to set up the database.
- Add SQL migration for initializing roles, schemas, and seeding vehicle data.
- Create leads and customers tables with appropriate policies and functions for CRM.
- Seed admin user and configure storage bucket with RLS policies.

.gitignore

@@ -0,0 +1,13 @@
+# Environment
+.env.local
+*.local
+
+# Bind-mounted runtime state (keep folder, ignore contents)
+/data/db/
+/data/storage/
+
+# OS / editor
+.DS_Store
+Thumbs.db
+.vscode/
+.idea/