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.
jsdom resolves no CSS Modules layout and reports scrollHeight === clientHeight
for every element, so the unit test cannot witness the scroll the .sources
max-height produces. Drive it in the real browser instead.
The web-search-round search double now returns 12 provider results with a
title, snippet, and date each. That pins the seam's cap end to end for the
first time in a real composition — searchMaxResults keeps 8, the model-visible
text carries the kept titles and none of the dropped URLs, meta.truncated is
true — and 8 such rows overflow the 320px container. A case after the aria
golden expands the row and asserts 8 <li>, no button, the truncation
indicator, and computed max-height/overflow-y with scrollHeight > clientHeight.
The recorded stream and the aria golden are unchanged: replay is a positional
cursor over the fixture's chunks and the search double is a separate local
endpoint, while the card is collapsed at capture time.
The READMEs of ui-primitives and ui-conversation still documented the
removed maxSources prop, DEFAULT_WEB_MAX_SOURCES, CHAT_WEB_MAX_SOURCES,
and the head/tail collapse; the 2026-07-30 frontend note described the
same as current behavior. Restate all of them as the fixed-height scroll
container and cross-link the two notes both ways.
Bound the model-visible/card-visible correspondence: spill-policy's
tools/post-execute replaces an oversized result's content while leaving
presentationMeta whole, so the card's contract is the view it receives,
not the model's context.
Narrow the unit test's name and header comment to what jsdom establishes
(one <ol>, no expand control); jsdom does not resolve CSS Modules layout,
so the scroll geometry belongs to an assembled browser case.
Replace the WebBlock search card's head/tail collapse and expand button
with a fixed-height scroll container that lists every source the tool
returned. The model-facing side is unchanged: the seam still caps sources
at searchMaxResults and the truncated indicator stays, so model-visible
and frontend-visible sources remain identical.
Remove CHAT_WEB_MAX_SOURCES and DEFAULT_WEB_MAX_SOURCES: with scroll, the
chat row and details panel show the same full list.
fz