#73 Subtask Support Implementation

[Anonymous]

Originally created by: plaintool

Requested by: JJK (jjkerneis@free.fr)

Requirements

1. Tree Building

2. Build the task tree structure based on indentation levels parsed from the file.

3. Collapse/Expand Functionality

4. Add controls to collapse/expand task levels.

5. Collapsed tasks should be hidden from the view.

6. Task Movement Rules

7. Moving nested tasks up/down is allowed only within the same level.
8. All subtasks must move together with the parent.
9. When tasks are moved to another group, their nesting level must be recalculated relative to the root of the target group.

Notes

• Must maintain full compatibility with the existing file format and task operations.
• The feature enhances task hierarchy management and visibility.