Use redirect instead of delivering index.html to prevent /ui paths in the future

Root cause: There are middlewares, which still use old redirects to /ui
Solution: To prevent 404s, we just serve the index.html

Solution: Only use the hash of the version

Root cause: Version has was updated before file cache
Solution: Keep all updates in one place and switch to new version at the same time

Root cause: If some of the UI containers is not available after successful start, the version update check might fail.
Solution: Add error handlers when manifests can not be fetched after startup

Fixes #6

since we don't expect admins to collect metrics for those services,
we provide them with some sensible defaults.

fixes potential security issue in swagger-ui

Root cause: Every readiness check triggered a cache warming
Solution: Move readiness to startup probe