CLI export doesn't work for text

Using the CLI export doesn't render text layers.

Steps to reproduce:
1. Make a new document in the latest web version of Graphite with `cargo run`.
2. Using the text tool, add some text to say "Test"
3. Save this file to the computer as `my_document.graphite` in your document folder
4. Export this file through the CLI with `cargo run cli -- export ~/Documents/my_document.graphite -o my_output.png --width 1920 --height 1080`
5. Observe that the resulting image is blank (or, if you had another layer in the artboard, the result is that other layer)

Other notes:
- This seems to be an issue for any of the 4 filetypes (png, jpg, svg, gif)
- I tried some workarounds, like converting the text to sample polyline or filling it with instance points, and these would also not render, so my guess is the Text node itself has some kind of issue.
- Unfortunately, I wasn't able to track down when this started, as the introduction of this bug goes beyond the current CLI syntax.

Reproduce the failure with the documented `cargo run cli -- export` command, then trace the CLI export path and how it handles Text nodes. Confirm the fix by exporting a document containing text to PNG, JPG, SVG, and GIF and verifying that the text renders.

Rédigé par le modèle d'indexation à partir du texte de l'issue.