Custom subscription templates only received the lastOnline timestamp, so
template authors had to fake an online indicator by comparing it against
the current time, and the page was a one-shot server render with no way
to refresh usage without reloading the whole HTML.
The template context (and window.__SUB_PAGE_DATA__) now carries isOnline,
computed from the panel's own online-client tracking (local xray plus
remote nodes) at render time. The subscription URL also answers
?format=info with the page view-model as JSON — minus the links, with
emails deduplicated — so templates can poll live status cheaply. The
shared view-model construction moved into buildSubPageData/subPageContext
so the HTML page, the SPA payload and the info JSON cannot drift apart.
Also documents the previously injected but undocumented announce
template variable.
Sanaei