Shinylive apps are not isolated

[davidchall]

Transferred from quarto-dev/quarto-cli#13404

There is an issue with how auxiliary source files are located for Shinylive apps, so these apps are not truly isolated (as implied by the standalone config field). If I create 2 apps with conflicting auxiliary filenames, then 1 app will attempt to load the auxiliary file from the other app. It appears to be a race condition which app is located, because the working app alternates randomly.

Here's a MBE (also available at https://github.com/davidchall/quarto-shinylive-bug):

---
title: Test
format: html
filters:
  - shinylive
---

## App 1
```{shinylive-python}
#| standalone: true

## file: app.py
from helper import helper1
from shiny.express import input, render, ui

ui.input_numeric("numeric", "Numeric input", 1, min=1, max=10)

@render.text
def value():
    return input.numeric()

## file: helper.py
def helper1():
    return "This is a helper function"
```

## App 2
```{shinylive-python}
#| standalone: true

## file: app.py
from helper import helper2
from shiny.express import input, render, ui

ui.input_numeric("numeric", "Numeric input", 1, min=1, max=10)

@render.text
def value():
    return input.numeric()

## file: helper.py
def helper2():
    return "This is a different helper function"
```

But App 1 fails to load with error:

  File "/home/pyodide/app_0wpouot7xx0ufdvibcl1/app.py", line 1, in <module>
    from helper import helper1
ImportError: cannot import name 'helper1' from 'helper' (/home/pyodide/app_uwgf7rt7kak5fn8bus6x/helper.py). Did you mean: 'helper2'?

[davidchall]

BTW: The generated test.html looks correct. Could this mean it is a shinylive bug instead of a shinylive quarto extension bug?

[gadenbuie]

I suspect there's an issue in shinylive itself. @wch, would you mind taking a look? @davidchall provided an excellent, minimal example in davidchall/quarto-shinylive-bug