sidebar: what each tab's panes are saying, said under the tab (tab_bar_status)

Panes already announce a one-line status over OSC 5577, and it rendered
in exactly two places -- both inside the pane's own frame, which is the
one place you are not looking when you most want it. The sidebar has
the vertical room the top strip never had: under each tab, up to
tab_bar_status rows of what the panes inside said, in tree order, dim
like the pane count. A dead pane's row says how it died instead
(exit_words), the same substitution its own frame makes.

The cap's last row is spent on an ellipsis rather than one more status
pretending the list is complete, and a status cut to the sidebar's
width ends in one too -- 'building 3' is a different fact than
'building 3/7'. Each row is a find: hit, the verb that already means
'go to this pane', so clicking a status jumps to the pane that said it,
across tabs. Freshness costs nothing new: an OSC status marks the pane
dirty, the same path the bell indicator rides out of background tabs.

1 files changed, 6 insertions, 0 deletions

diff --git a/docs/slosh.5 b/docs/slosh.5
index c605ab4..367d79e 100644
--- a/docs/slosh.5
+++ b/docs/slosh.5
@@ -135,6 +135,12 @@ The strip's indicators move to the sidebar's bottom rows; the status line
 keeps the full width. A terminal too narrow to give up the columns falls
 back to \fBtop\fR until it grows.
 .TP
+.BI tab_bar_status\  n
+Under each of a sidebar's tabs, up to \fIn\fR rows of what the panes inside
+said through OSC 5577 status \(em or how they died \(em with an ellipsis when
+there was more. Clicking a status row jumps to the pane that said it.
+0 turns it off; \fBtop\fR has no room for it either way.
+.TP
 .BI hints\  bool
 What the pointer is resting on, said in the status line.
 .TP