feat: add settings and reports pages

- Add settings page with organization, sites, courts, and users tabs
- Add reports page with revenue charts and statistics
- Add users API endpoint
- Add sites/[id] API endpoint for CRUD operations
- Add tabs UI component
- Fix sites API to return isActive field

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

scripts/init-db.sql

@@ -0,0 +1,8 @@
+-- Padel Pro Database Initialization
+-- This script runs when PostgreSQL container starts for the first time
+
+-- Enable UUID extension if needed
+CREATE EXTENSION IF NOT EXISTS "uuid-ossp";
+
+-- Grant privileges
+GRANT ALL PRIVILEGES ON DATABASE padel_pro TO padel;