chore: remove feature flag from DONE status

[Achintya-Chatterjee]

Issue Description

The task status currently displays COMPLETED in the system. The status should be updated to DONE to align with updated terminology and improve clarity. This change will impact multiple components, APIs, and test cases that utilize the COMPLETED status.

Expected Behavior

1. Task statuses in all relevant locations (UI and API responses) should display DONE instead of COMPLETED.
2. The updated status should be reflected in:

• Task Details Page
• Dropdown Menus for Task Status
• API Responses for task details
• Mock Data and Unit Tests

Current Behavior

1. The status is displayed as COMPLETED across the system.
2. UI and API logic rely on the COMPLETED status, causing inconsistency with the new naming convention.

Screenshots

without dev=true

with dev=true

Reproducibility

• This issue is reproducible
• This issue is not reproducible

Steps to Reproduce

1. Open the details page for any task.
2. Check the status field; it will display COMPLETED.
3. Look at the dropdown menu for status updates; COMPLETED appears instead of DONE.

Severity/Priority

• Critical
• High
• Medium
• Low

Checklist

• I have read and followed the project's code of conduct.
• I have searched for similar issues before creating this one.
• I have provided all the necessary information to understand and reproduce the issue.
• I am willing to contribute to the resolution of this issue.

[vaishalimaheshwari2000]

Please assign this task to me