I modified the proxy host cache we already had and were using for
websocket csp headers to also include the wildcard app host, then used
those for frame-src policies.
I did not add frame-ancestors, since if I understand correctly, those
would go on the app, and this middleware does not come into play there.
Maybe we will want to add it on workspace apps like we do with cors, if
we find apps are setting it to `none` or something.
Closes https://github.com/coder/internal/issues/684
* chore: add /v2 to import module path
go mod requires semantic versioning with versions greater than 1.x
This was a mechanical update by running:
```
go install github.com/marwan-at-work/mod/cmd/mod@latest
mod upgrade
```
Migrate generated files to import /v2
* Fix gen
* chore: Implement workspace proxy health check cron
At a given interval will check the reachability of workspace proxies.
* Proxyhealth is an enterprise feature
* Start proxyhealth go routine on enterprise coder
