Bundle Quarto with Positron

[jmcphers]

This change bundles the Quarto CLI and all of its requisite tooling (deno, typst, etc.) with Positron, replacing the former Pandoc-only approach. Quarto is currently version-pinned at 1.5.55.

The Quarto bundle is stored in the quarto subdirectory of the app root.

Addresses #3705.

Important

This change alone is not sufficient to allow the Quarto extension to discover the copy of Quarto bundled in Positron; the Quarto extension's search path is not configurable, so a separate change will need to be made to the Quarto extension to include the Positron app directory in the search path. I'll make that change once this one has landed successfully.

QA Notes

• This change needs to be tested on all 3 platforms.
• The Quarto extension does look on the PATH for Quarto, so if you're feeling brave you can cause it to use this bundled version of Quarto by putting it on your PATH.
• This change uses a different version of Pandoc and puts Pandoc in a new location. Make sure that RSTUDIO_PANDOC points to a folder that contains the pandoc executable, and that rmarkdown::find_pandoc() and the "Render R Markdown" command are able to use the new Pandoc.
• Both the Quarto extension and R Markdown package will find Quarto/Pandoc on the PATH, so to ensure you're testing against the embedded copy of Quarto and Pandoc in Positron, make sure to remove any other installations of Quarto and Pandoc on your PATH (or temporarily modify your PATH so they aren't discovered)
• It is expected that this change will dramatically increase the size of the installers.

[coatless]

@jmcphers, is there any chance the first version of Positron with an embedded copy of Quarto could have an updated copy of Quarto extension built-in with the fix? Or is the fix + update something that will immediately follow (< 24 hours)?

[jmcphers]

@coatless It'll definitely be more than 24 hours as this change still needs reviewing and building, and I haven't finished the changes to the Quarto extension yet. In flight, stay tuned!

[petetronic]

Thanks Jonathan, I've rebuilt installers for Mac and Linux with this branch and confirmed they are bundling Quarto 1.5.55 (and understand the extension needs to be updated before it will find them in this new location). I'll rebuild Windows now too just to complete the set.

[petetronic]

Windows also bundled Quarto 1.5.55

[petetronic]

I was also able to update my PATH to the bundled Quarto and it attempted to use it when previewing a .qmd, but it ran into permission issues compiling the theme on MacOS.

quarto preview /Users/username/dev/scratch/bugs/Untitled-1.qmd --no-browser --no-watch-inputs
~/dev/scratch/bugs: quarto preview /Users/username/dev/scratch/bugs/Untitled-1.qmd --no-
browser --no-watch-inputs
ERROR: Theme file compilation failed:

/Users/username/dev/git/posit/VSCode-darwin-arm64/Positron.app/Contents/Resources/app/quarto/bin/tools/aarch64/dart-sass/sass: line 20: /Users/username/dev/git/posit/VSCode-darwin-arm64/Positron.app/Contents/Resources/app/quarto/bin/tools/aarch64/dart-sass/src/dart: Permission denied

[jmcphers]

@petetronic thanks, I just saw this in my own testing as well this morning! Should be addressed in 6c3c0a6.

[petetronic]

Nice, I confirmed adding the executable flag to the dart binary resolved the error.