Add unit tests for Tasks Management route handlers

[Copilot]

Adds unit test coverage for the Tasks Management route handlers (tasks_management.go).

Test Coverage

• DeleteTask - method validation, task ID parsing, not found/forbidden/error handling, success case
• EditTask - method validation, task ID parsing, multipart form handling without archive, error cases
• GetAllCreatedTasks - method validation, pagination context, authorization, empty/populated results
• GetLimits - method validation, task ID parsing, error handling, empty/populated limits
• PutLimits - method validation, JSON body validation, task ID parsing, error handling, success case

Tests follow existing patterns using gomock for service mocking and httptest for request simulation.

func TestDeleteTask(t *testing.T) {
    ctrl := gomock.NewController(t)
    ts := mock_service.NewMockTaskService(ctrl)
    route := routes.NewTasksManagementRoute(ts)
    
    // ...
    
    t.Run("Success", func(t *testing.T) {
        ts.EXPECT().Delete(gomock.Any(), gomock.Any(), int64(1)).Return(nil)
        // assert 200 OK with success message
    })
}

Original prompt

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This section details on the original issue you should resolve

<issue_title>Tasks Management route unit tests</issue_title>
<issue_description></issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Tasks Management route unit tests #196

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[Copilot]

Pull request overview

This PR adds comprehensive unit test coverage for five Tasks Management route handlers: DeleteTask, EditTask, GetAllCreatedTasks, GetLimits, and PutLimits. The tests follow established patterns from existing route tests (e.g., contests_management_test.go), using gomock for service mocking and httptest for request simulation. Each handler is tested for HTTP method validation, error handling (not found, forbidden, internal errors), and success scenarios.

Key Changes

• 771 lines of test code covering all major code paths for the five route handlers
• Tests validate HTTP method restrictions, ID parsing, authorization, error propagation, and response formatting
• Mock setup follows clean architecture pattern with TaskService interface mocking