feat: add Corteza Cloudron package (Low-Code)

- Create Dockerfile downloading pre-compiled binaries
- Add CloudronManifest.json with PostgreSQL and localstorage addons
- Create README.md with comprehensive low-code platform documentation
- Add .env.example for environment configuration
- Add CHANGELOG.md for version tracking
- Add logo.png (Corteza branding)

Corteza is an open-source low-code platform for building
database-driven applications without coding.

Package includes:
- Ubuntu 22.04 base with pre-compiled Corteza binaries (436MB)
- PostgreSQL addon for database storage
- Localstorage addon for application data
- Multi-stage download (simpler than building)
- Comprehensive documentation with visual builder examples
- Form builder, report builder, page builder examples
- User management and permissions documentation

Features supported:
- Visual app builder with drag-and-drop
- Form builder for data entry
- Report builder for custom reports
- Page builder for application pages
- API builder for REST APIs
- Workflow automation with triggers
- Database-driven applications
- Multi-tenancy support
- User management with role-based permissions
- Record management with import/export
- Theme customization
- Mobile-responsive design
- Audit trail
- Security features (row-level permissions)

Environment variables:
- CORTEZA_VERSION: Corteza version (default: 2022.9.0)
- STORAGE_PATH: Data storage path (default: /app/data)
- HTTP_ADDR: HTTP address (default: 0.0.0.0:80)
- HTTP_WEBAPP_ENABLED: Enable web app (default: true)

Ports:
- 80: Main HTTP port (web interface)

Addons:
- PostgreSQL: Database storage
- Localstorage: Application data

💘 Generated with Crush

Assisted-by: GLM-4.7 via Crush <crush@charm.land>

Package-Workspace/Low-Code/corteza/logo.png

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