Navigation tree present odd results with the Filesystem backend

Reproduction steps

1. Init ~/.cristal with the content described below
2. Start an electron instance and open a configuration using the filesystem backend
3. Check the navigation tree

Expected

The navigation tree contains:

• Index
• newpage
  • subpage

Actual

The navigation tree seems to contain the nodes, but with empty labels.

Click on the nodes does not open the corresponding pages.

~/.cristal content

index/page.json

{
  "name": "",
  "source": "Hello world",
  "syntax": "markdown/1.2"
}

newpage/page.json

{
  "name": "",
  "source": "New page",
  "syntax": "markdown/1.2"
}

newpage/subpage/page.json

{
  "name": "",
  "source": "aaaaa",
  "syntax": "markdown/1.2"
}