Merge Feat/task-management branch into main - Add task CRUD UI (modal form, detail view, menu), toasts, API alteration and unit tests

[arsalanrasheed93]

Summary:

FE:

• Added interactive task creation/edit/delete flows in the frontend.
• Used modal form (TaskForm / AddNewTask), task detail view, three-dot menu for per-task actions, and toast notifications.
• Integrated with backend endpoints: GET /api/tasks, POST /api/tasks (create), PUT /api/tasks/:id (update), DELETE /api/tasks/:id (delete).
• Integrated key press functionality

BE:

• Introduced a service layer to handle business logic and keep controllers thin.
• Added DTOs (TaskCreateDto and TaskUpdateDto) to decouple API request/response from the database model.
• Refactored repository to work with IDataContext and implemented soft delete (IsActive = false).
• Implemented unit tests for TaskService using NUnit and Moq to validate all CRUD operations.
• Added middleware for exception handling