The C0R3 rebuild queue only linked out to the logs page (logs →). Add an
inline live-log panel under the queue that streams the currently-running
rebuild's build output, so the operator watches progress without leaving the
page.
Extract the build-log SSE streaming logic (append stdout/stderr, sticky-bottom
scroll, stderr separator, reconnect-replay reset, done/error handling) into a
shared `openBuildLogStream(id, pre, {onDone, onError})` in common.js, and use it
from BOTH the L0GS page BUILD tab (logs.js, previously inline) and the new C0R3
panel (core.js) — one implementation, no duplication.
The panel is one persistent instance keyed to the running entry's build_log_id
(the queue runs one build at a time), in its own container (#rebuild-live-log)
outside rebuild-queue-section so the queue's per-row re-render — rows rebuild as
the build step advances — never tears down the open stream; it reconnects only
when the running build_log_id changes and won't reopen a stream that already
sent done. Collapsible, live/ok/fail badge, raw download. Hidden when nothing
is building; each row keeps its logs → link for full history.
Frontend-only — no backend change (endpoint + build_log_id already existed).
Closes#1860.