Writing the tag into index.html on disk fails on most fresh installs
(linuxserver image, distro packages, Docker as a normal user) because
the web files belong to root. A middleware now adds the tag to the
response instead, so the ShareLink action and the guest lockdown work
right after install. The on-disk edit stays as a best-effort extra, and
the tag uses a relative src so it also works under a base URL.
Bump to 1.0.8.0.
