After a session's first load per page, a tab switch fetched a 1 MiB tail of
the server's byte stream. For a fullscreen claude pane (alternate screen,
tmux `history_size` 0) that tail is old repaints of one frame, and an idle
tab parsed it twice (the cached copy, then the fresh one).
Every terminal response now records `paneHistoryLines` per session, and
`selectSession` takes `full=1` whenever the last report was 0. For such a
pane that capture is the visible frame, a few KB, which is also what a page
load already shows. A response without the field forgets the entry, so
unknown never counts as empty; a pane that starts keeping history goes back
to the tail on the next switch. Shells and the refresh path are unchanged.
Measured with real prod payloads through the real client in chromium:
median switch 1.26-1.66 s -> 0.10-0.19 s, parse ~1.1-1.5 s -> 2-3 ms.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Codeman maintainer
df1a493b8c