Company & Client Relationship Tracker

High-Level Description This application is a task and service management solution designed to help businesses track and manage services provided to companies, organize related tasks, and handle invoicing. The system allows users to manage key entities such as companies, contacts, employees, and services, while supporting features like task scheduling, priority management, and reporting. The application is designed to streamline workflows, ensuring that upcoming tasks are generated automatically based on service frequencies, and enabling efficient management of invoices for completed work. It is intended to be used by administrators and other role-based users, with access control to sensitive financial data. Technology Stack Frontend: C# WinForms for the desktop application, providing a user-friendly interface for interacting with the system. Backend: SQLite database for lightweight, embedded data storage, providing fast and reliable persistence for application data. Other Tools: Standard .NET libraries and WinForms components for data binding, validation, and UI rendering. Key Requirements Data Entry and Management: Full Create, Read, Update, Delete functionality for core entities: Company, Contact, Employees, and ServicesOffered. The ability to search for Contacts by first name, last name, email, phone number, or associated company. Companies can be searched by both their legal and operating names. Company records support multiple owners and managers (stored in the Contact table), and the system should handle these relationships. Service Tracking and Task Management: The system will track the services offered to each company, including the frequency of each service (configured using the reference tables). Based on these services and their frequencies, the system will automatically generate upcoming tasks, with configurable time periods (e.g., monthly, or custom date ranges). Tasks can be assigned priorities, notes, and calculated due dates based on the service start date and frequency (e.g., monthly tasks due 30 days after the start date). Reporting and Task Filtering: Tasks should be reportable by status (e.g., outstanding, upcoming, in-progress) and sortable by associated company, owner, or manager. Manual task creation will also be supported for flexibility. Invoicing: The application will generate invoices based on completed tasks. Invoices can be queried, marked as paid or partially paid, and updated with notes. Invoice management will be restricted to Admin users only, with role-based access control ensuring sensitive financial information is properly safeguarded. The ability to query invoices by company or owner is required for efficient tracking. Admin Access and Role-based Security: Only Admin users will have access to financial data and invoice management functionality, ensuring that sensitive information is properly controlled.   attached file has suggestion for the entity relationships. Also included some technical details on requirements.