hierarchy-tree

# Building ASCII Trees from Parent/Child Data

When you have flat parent/child data, construct the tree visually using LLM reasoning - NO CODE NEEDED.

## Step 1: Get the Data

Query work items with their parent:
```bash
az boards query --wiql "SELECT [System.Id], [System.Title] FROM workitems WHERE [System.WorkItemType] = 'Feature' AND [System.TeamProject] = 'ProjectName'" -o json
```

Then for each item, get its parent via relations (System.LinkTypes.Hierarchy-Reverse).

The result is flat data like:
```
ID     Parent   Title
1517   1509     Feature A
1518   1509     Feature B
1759   1827     Feature C
1827   1509     Feature D
```

## Step 2: Build the Tree (LLM Reasoning)

1. **Find roots** - Items whose Parent is not in the ID list (or is an Epic/external)
2. **Group children** - For each ID, collect all items where Parent = that ID
3. **Recurse** - Build subtrees for each child

From the example above:
- Root: 1509 (not in ID list as a child)
- 1509's children: 1517, 1518, 1827
- 1827's children: 1759

## Step 3: Render ASCII

Use these characters:
```
|   = vertical continuation (more siblings below)
|-- = branch to sibling (more siblings follow)
`-- = last branch (no more siblings)
    = indent (4 spaces under a last branch)
```

Rules:
- Each level indents 4 characters
- Use `|-- ` for all children except the last
- Use `` `-- `` for the last child
- Continue `|   ` vertically when parent has more siblings

## Example Transformation

**Input data:**
```
ID    Parent  Name
100   -       Root
200   100     Child A
300   100     Child B
400   300     Grandchild B1
500   300     Grandchild B2
600   100     Child C
```

**Output tree:**
```
#100 Root
|-- #200 Child A
|-- #300 Child B
|   |-- #400 Grandchild B1
|   `-- #500 Grandchild B2
`-- #600 Child C
```

## Complex Example

**Input:**
```
ID    Parent  Name
1     -       Epic
10    1       Feature A
11    1       Feature B
20    10      Sub A1
21    10      Sub A2
30    11      Sub B1
31    30      Deep B1a