The overview page decided whether the host is up with a TCP probe of
the compute's hostname. For an ssh compute named by an ssh_config alias
or reached through ProxyJump, that name and port cannot be reached from
WebVirtCloud directly, so the probe failed while the connection worked:
the page showed the host details and never started the CPU and memory
graphs. The overview now uses Compute.status, the connection
WebVirtCloud uses for everything else.
The compute list shows why a host is not connected (Compute.connection_error)
under "Not Connected", for example a host key verification failure.
Checked against the ssh compute of the test setup through an
ssh_config alias: the previous code renders the overview with the
graphs off, the new one with them on. Both new tests fail on the
previous code.
