#1381 landed the bar's horizontal position; this branch decides when it is
drawn. The e2e keeps both scenarios and the golden carries both palettes'
pointer-state readings alongside the new edge-offset lines.
Review findings from the first round:
- ui-settings renders its full-viewport panel as a fixed-position DESCENDANT
of the sidebar column, so `pointerleave` never fires when the pointer moves
onto it and the bars stayed drawn after it closed. Leaving is now decided
against the column's box from a document-level pointermove that exists only
while the bars are drawn; the element's own leave stays for the pointer that
leaves the window.
- The rebind gate judges the rule rather than each declaration, so a pair that
mixes `transparent` with an l2 hover no longer passes, and the elevation
half compares whole values instead of token shape.
- Hiding no longer exempts a sheet from the elevated-surface rebind check.
- The e2e polls the reveal before reading a colour for the golden, and pins
that a pointerless scroll draws no thumb.
The session list overflows after a handful of sessions, and its scrollbar
was drawn permanently in a column that is at rest most of the time.
SidebarRoot now tracks the pointer over the whole column and rebinds
ui-theme's scrollbar indirection pair to `transparent` while it is
outside, keeping the thumb for 2s after the pointer leaves so it does not
blink out on the way past. Rebinding colour leaves the list's
`scrollbar-gutter: stable` reservation in force, so revealing the bar
moves no row.
ui-theme's gate now states the widened contract: a rebind targets an -l2
token pair or `transparent`, and nothing else.
session-title already registers a title projection unit; /resume now
reads it instead of scanning logs: live rows from the registry
snapshot, persisted rows from the durable checkpoint row
(cachedSnapshot, zero I/O), and only rows without a usable checkpoint
pay a coldSnapshot — checkpoint plus readFrom tail, written back so the
next scan is metadata-only. Cold reads are bounded by the new
resumeScanConcurrency config; compositions without the cache fall back
to the bounded readTitleSnapshots batch. The TUI overlay mounts the
projection registry, storage, and projection-cache rows over the same
storages root the web surface uses, so checkpoints serve both.
master's new disclosure test pins the literal the abort backport retired;
the seeded cancel fixture now carries 'Error: tool call aborted', so the
test literals and the ARIA golden follow (replay-verified on Linux).