AddViteApp should auto-configure IsProxied = false or support HMR through the proxy

[maddymontaquila]

Is your feature request related to a problem?

When using AddViteApp with the default Aspire proxy enabled, Vite's Hot Module Replacement (HMR) websocket connection fails. The workaround is:

.WithEndpoint("http", endpoint =>
{
    endpoint.Port = 5173;
    endpoint.IsProxied = false;
})

This requires:

1. Knowing that IsProxied = false exists
2. Hardcoding Vite's default port (fragile — conflicts if another Vite app is running)
3. Losing Aspire's request tracking for the frontend

Describe the solution you'd like

Option A: AddViteApp should set IsProxied = false by default, since HMR doesn't work through the proxy.

Option B: The Aspire proxy should support websocket passthrough for HMR.

Additional context

Discovered in a project using AddViteApp + WithPnpm() with a React 19 + Vite frontend on Aspire 13.2.0-preview.1. The app loads fine but HMR silently fails — file edits don't hot-reload — until IsProxied = false is explicitly configured. This pattern is undocumented and was found through trial and error.

[davidfowl]

I’m not sure this is true. Or I’ve been using something that isn’t hot module reload with vite 😅