feat: implement administrative section with authentication and seed data
## Features Added
### Admin Login Page (public/login.html)
- Professional login UI with Bootstrap 5
- Email/password authentication
- CSRF protection
- Rate limiting protection
- Session persistence (7 days)
- Remember me functionality
- Language: Spanish with translations ready
### Authentication Middleware (src/server/index.ts)
- Session-based authentication using SQLite
- bcrypt password hashing
- CSRF token endpoint for form protection
- Auth check on admin.html page load
- Logout endpoint
### API Client Enhancements (public/js/api.js)
- Added auth methods: login(), logout(), getMe(), getCsrfToken()
- CRUD methods for all admin entities:
- Properties: create, update, delete
- Leads: get, update, delete
- Testimonials: create, update, delete
- FAQ: create, update, delete
- Services: create, update, delete
- Settings: get, update
- Admin stats endpoint
### Comprehensive Seed Data (src/db/seed-comprehensive.ts)
- 36 properties of all types:
- 8 urban lands
- 10 agricultural plots
- 8 houses/villas
- 10 apartments
- Real Tenerife locations with coordinates
- Spanish and Russian translations
- 8 testimonials from international clients
- 8 FAQ items (buying process, taxes, etc.)
- 6 services offered
- Admin user: admin@tenerifeprop.com / admin123
- Stock photos from Unsplash
### Tests (tests/auth.test.ts)
- Authentication tests
- Session management tests
- Property CRUD tests
- Input validation tests
- XSS prevention tests
- Email/phone validation tests
## Why These Changes
1. Security: Authentication protects admin routes from unauthorized access
2. Data: Seed data provides realistic content for testing and demo
3. UX: Professional login page improves user experience
4. Testing: Tests ensure reliability and catch regressions
## Breaking Changes
None - all changes are additive
## Related Issues
- Closes #28 (Admin Login Page)
- Closes #29 (Seed Data Generation)
- Closes #30 (Tests Implementation)
## Milestone
Administrative Section Implementation (#51)
e6ea1400d6