an error while running the default app

Hi! I was trying to use dart webdev for a quick website, but I ran into some issues regarding the webpage.

When I run `webdev serve` and go to the page `127.0.0.1:8080`, i get an empty page.

After that, I look at my terminal, and see dart spamming this:
```
[WARNING] Error serving requestsSocketException: Connection reset by peer (OS Error: Connection reset by peer, errno = 54), address = 127.0.0.1, port = 8080
```
What does it mean???

Then I think that something is wrong with loading the JS files, like `main.dart.js`, but again, no. I get no network errors, no browser console errors, nothing except these cryptic warnings in the terminal!

And also when I build it (`webdev build`) and run the HTML page in the browser - it is **completely fine and working!**

# recreation
I use MacOS Sonoma 14.4\
webdev V3.5.0\
`Dart SDK version: 3.4.1 (stable) (Tue May 21 15:46:25 2024 +0000) on "macos_arm64"` (installed using homebrew)\
PyCharm 2024.1.4 (Professional Edition)

to get this empty website, i ran `dart create -t web . --force` and later `wedev serve`

Start by reproducing the issue with `dart create -t web . --force` and `webdev serve` on macOS Sonoma, using the reported Dart and webdev versions, then compare it with `webdev build`. Done means identifying why the served page is empty and why the terminal reports connection resets, or documenting the missing diagnostic information needed to proceed.

Written by the indexing model from the issue text.