Show a remote host's state and next step on its reviews

[thesiti92]

Shows a remote host's state the same way everywhere, with one next step, instead of raw error text.

• A dropped review stream shows a yellow chip in the top bar ("alex-box offline") instead of the "Connection lost. Reconnecting…" banner. Its click runs the host's next step: Retry, Install, or Open Settings. Retry also reopens the review stream at once instead of after its backoff.
• reviewHostStatus gives each host state one short label, a sentence and that next step. The chip, Home, Settings and the gateway's messages use it.
• A remote review that has not loaded says what its host is doing, with the next step, instead of a blank page.
• On Home, an unavailable review says why, with the next step, and opens once its host is back.
• Settings offers Retry to offline hosts, shows progress and errors for Retry and Install, and shows the host's detail without the state name in front. Open Settings from a review scrolls to Remote hosts.
• The top bar's context group can shrink, so the chip and agent badges end in an ellipsis instead of pushing Dismiss off the bar.
• Gateway errors no longer say "did not answer: it did not answer", and unknown network codes read "it failed (CODE)".

Stacked on #949.

Test plan

• With a host added, pause it (remote.mjs pause a): the chip shows " offline" with Retry, and hovering shows the reason.
• Reload the window while the host is paused: the review tab shows the host's state and Retry.
• On Home, click the paused host's review: the message gives the reason and Retry. Resume the host: the review opens.
• Settings: the paused host's row has Retry. Open Settings from a review's chip on an auth-failed host scrolls to Remote hosts.
• remote-host journey passes.