docs(client-web): sync the web card contracts to the scrolling source list

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.

packages/client/ui-conversation/README.md

@@ -22,7 +22,7 @@ Generic tool rows classify the built-in bash, read, search, write, edit, and run
 
 A tool call declaring the `terminal` render intent renders its command output inline, at both conversation render sites, through ui-primitives' `TerminalBlock`. `contract/terminal-card-model.ts` is the single derivation from the snapshot's `callView`/`resultView` pair, so the sites cannot disagree about a command, its cwd, or its exit status; it yields null — the generic path — for any other card tag, including one this client version does not know. Both sites therefore also show the card's run-state dot, which is the same `StateDot` semantic a tool row's leading icon carries, so a row and its own card always agree about one command's state. A multi-line command gets one prompt row per line, with the dot marking the call once on the first row — the exit status is the whole call's, so a dot per line would claim a per-line outcome bash does not report. The keyed `BashRow` carries the card resident below its summary row; since tool rows are no longer details-panel click targets, the card's copy and expand controls are the row's only interactions. The render-site fallback row keeps the card behind its existing expand control. Rows cap at `CHAT_TERMINAL_MAX_LINES` (8) against the panel's 16, which is what keeps a summary surface bounded — the panel stays the single-call reading surface. Inline output is licensed per render intent — the terminal and web cards, each with its own bound. A Bash execution failure that settles on the generic path instead exposes its original arguments and full error through the same bounded IN/OUT disclosure, while successful generic results such as a background-start acknowledgement remain summary-only ([decision](../../../.agents/notes/implemented/feature/2026-07-28-web-terminal-card.md)).
 
-A tool call declaring the `web` render intent renders its web retrieval inline, at both conversation render sites, through ui-primitives' `WebBlock`. `contract/web-card-model.ts` is the single derivation from the snapshot's `resultView`, mirroring the terminal card, so the sites cannot disagree about what a web call shows; it yields null — the generic path — for a running call, a non-web result view, a generic result view, a `card` tag this client version does not know, or a web card whose `kind` this client version does not know (a newer host's value, which the wire cannot be trusted to be `search` or `fetch`). The keyed `WebRow` registers one component under both `web_search` and `web_fetch`, discriminating on the tool name only for its icon and title; it composes the shared `ToolRow`, feeding the card as ToolRow's `web` body, so the retrieval is the row's collapsed-by-default expanded card (the same unified expand every card row has). A web-declaring tool without a keyed row lands on the `GenericToolCard` fallback, which routes the card through ToolRow the same way, and the details panel renders it at the primitive's full source allowance and, below the card, the flattened model-visible result content — a fetch body is readable only there, since its card carries only the URL and status. Rows cap at `CHAT_WEB_MAX_SOURCES` (8) against the panel's 16, the same summary-versus-reading split the terminal card draws ([decision](../../../.agents/notes/implemented/feature/2026-07-30-web-result-card-frontend.md)).
+A tool call declaring the `web` render intent renders its web retrieval inline, at both conversation render sites, through ui-primitives' `WebBlock`. `contract/web-card-model.ts` is the single derivation from the snapshot's `resultView`, mirroring the terminal card, so the sites cannot disagree about what a web call shows; it yields null — the generic path — for a running call, a non-web result view, a generic result view, a `card` tag this client version does not know, or a web card whose `kind` this client version does not know (a newer host's value, which the wire cannot be trusted to be `search` or `fetch`). The keyed `WebRow` registers one component under both `web_search` and `web_fetch`, discriminating on the tool name only for its icon and title; it composes the shared `ToolRow`, feeding the card as ToolRow's `web` body, so the retrieval is the row's collapsed-by-default expanded card (the same unified expand every card row has). A web-declaring tool without a keyed row lands on the `GenericToolCard` fallback, which routes the card through ToolRow the same way, and the details panel renders it and, below the card, the flattened model-visible result content — a fetch body is readable only there, since its card carries only the URL and status. Both render sites show the same complete source list — the one the tool returned and the model saw — bounded only by the card's own scroll container height, with no row-versus-panel cap ([decision](../../../.agents/notes/implemented/feature/2026-07-30-web-result-card-frontend.md), [source scroll](../../../.agents/notes/implemented/feature/2026-08-03-web-search-source-scroll.md)).
 
 A `read` call declaring the `read` render intent renders the returned file window inline, at both conversation render sites, through ui-primitives' `ReadBlock` — the line-numbered, syntax-highlighted content the tool projects. `contract/read-card-model.ts` is the single derivation from the snapshot's `resultView`; the read card is result-side only (a call carries no file content until `execute` returns), so a running read shows its summary alone and it yields null — the generic path — for a non-read result view or a `card` tag this client version does not know. The keyed `ReadRow` composes the shared `ToolRow`, feeding the card as ToolRow's `read` body, so it is the row's collapsed-by-default expanded card; the summary stays a path link that opens the file through the host. The render-site fallback and the details panel are read-aware too. Rows cap at `CHAT_READ_MAX_LINES` (8) against the panel's 16 ([decision](../../../.agents/notes/implemented/feature/2026-07-30-web-read-card-frontend.md)).