#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.
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).
Making `.sources` a scroll container turned its `padding-left` from spacing
into a correctness constraint. A scroll container clips inline-start overflow
with no way to scroll it back, and `::marker` is right-aligned to the content
edge, so past nine sources the markers rendered as `0.` and `1.` where `10.`
and `11.` belonged.
`searchMaxResults` is an unbounded positive integer, so size the padding in
`em` against the list's own font to hold a three-digit marker. The browser e2e
measures a `999. ` marker in that inherited font and requires the computed
padding to be at least that wide, pinning the room against the widest marker
rather than one fixture's source count.