I'm sorry, I do not have any public examples. I think unfortunately even the private repos I have in mind do not fully explore this approach. Typically my group's clients do not require us to account for disabled JavaScript.
Below is a small example application showing how to serve up a page with an embedded shiny application. Within the HTML you can use a <noscript> tag to include a message for users who have disabled JavaScript, see here for more on the <noscript> tag.
This is something of a toy example. In practice I would probably use a non-R web server to serve up the static pages. I hope this helps.
library(httpuv)
library(htmltools)
runServer(
host = "0.0.0.0", port = 8080,
app = list(
call = function(req) {
list(
status = 200,
headers = list(
`Content-Type` = "text/html"
),
body = as.character(
tags$div(
style = "margin: 2rem 0 0 2rem;",
tags$noscript( # <- <noscript>
style = "color: red;",
"Sorry, it looks like you have JavaScript disabled.",
"Many features of this site may not work as intended."
),
tags$iframe( # <- <iframe>
style = "width: 80vw; height: 80vh;",
src = "https://gallery.shinyapps.io/050-kmeans-example/"
)
)
)
)
}
)
)