[FEATURE] Add SubTasks in TaskCreate

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

I often need to have multiple subtasks associated with higher level TODO tasks. I currently have to keep track of those subtasks separately from the TaskCreate feature.

It would be great to have an integrated experience so that all high level and individual subtasks can be tracked by the TaskCreate feature.

Proposed Solution

Allow subtasks to be associated with addBlocks / addBlockedBy

Alternative Solutions

_No response_

Priority

High - Significant impact on productivity

Feature Category

Interactive mode (TUI)

Use Case Example

Example scenario:

1. Working on an HPC specific feature
2. That feature has a TODO list, and each item in the list has a subtask that needs to be done

Additional Context

_No response_