YAML filename autocompletion in Positron

When editing an .R script or .qmd file Positron (like RStudio) has an autocomplete interface to help select files in your project folder/workspace.

I was wondering whether it would be possible to enable something similar when editing Quarto YAML, as it would be rather useful to have this when editing _quarto.yml to list the chapters of a book for example.

Aware of the globs but still think this would be useful in other parts of the YAML tree too, like sidebars/listings, theme/css, or include-before-body etc.

There is already YAML autocomplete support for keys and values. But admit that I don't know how difficult it would be to limit file autocompletion only under book: chapters: (and other relevant parts of the tree) since I can imagine having the file autocomplete turn up elsewhere when editing the YAML file could get very annoying. An alternative would be to activate the autocomplete/file lookup by a shortcut key.

Apologies if not the right repo (and if there's a shortcut key but I don't know it).

The issue concerns existing YAML key and value autocomplete in Positron and _quarto.yml; start by locating the implementation of that autocomplete. Determine how file suggestions could be limited to relevant YAML tree locations or invoked by a shortcut, then verify that file completion appears in supported contexts without becoming noisy elsewhere.