LOG viewer — region header + CGROUP fold

Normative = the in-LOG header (search left · unfold-all + copy right) and the fold behaviour. Everything drawn as window/tab chrome is scaffold. The old tab-bar copy button is shown removed (per decision). Fold carets ( > folded / v open ) sit on the rail as they do today.

LOG
MENTOR
JSON
OPTIONS
— copy btn removed — ⧉
2 / 3
load_customers
1 warn
exit 02.4s
>
>
>
v
[NODE] ▶ started 14:22:07
[CONFIG] config - 3 lines
[NSJAIL] sandbox - 5 lines
[SQL] generated SQL - 12 lines
[STDOUT] reading customers.csv (18,204 rows)
[STDOUT] wrote warehouse/customers.parquet
[STDERR] 3 rows dropped: null primary key
[RUNNER] node finished in 2.41s
[CGROUP] cgroup - 4 lines
[CGROUP] cpu.usage 2.31s
[CGROUP] memory.peak 412 MiB
[CGROUP] memory.limit 512 MiB
[CGROUP] pids.peak 7
[NODE] finished — success · exit 0 · 14:22:09 · 2.4s

Search (A1, highlight-in-place): matches highlighted across the log; a hit inside a folded section auto-unfolds it (here the folded CGROUP opened for the two memory hits — the 3rd match is in the still-folded generated SQL, and it too would open). 2 / 3 = current match / total; Enter jumps to the next.
Unfold-all (double-chevron-down) opens every section; once all are open it flips to double-chevron-up = fold-all.
Copy copies the visible lines only — folded section bodies (config/sandbox/SQL here) are excluded, their one-line headers stay.
CGROUP is now its own foldable section, kept at the end (it summarises the run); default folded, auto-opens on a warn/error.