fix(web-search-card): surface truncation recovery, widen cardless fallback, validate wire shape, fix tail-cap

Address the ds-review-bot findings on the search card:

- searchCardModel dropped the result view's `content`, so a capped search's
  `Full … stored at: <locator>` recovery footer vanished from the UI (the card
  replaces the raw text). Thread it through as `SearchCardModel.recovery` and
  render it below the card at all three sites, only when truncated.
- SearchRow's fallback body was gated on `state === 'error'`, so a settled
  non-error call with no card (a successful nested run_code sub-dispatch, a
  legacy generic result) showed only its summary with content lost. Widen it to
  any settled call with `search === null`.
- searchCardModel trusted the `files`/`paths` shape the host wire schema only
  string-checks; a malformed known-kind frame would crash SearchBlock. Validate
  the full shape and fall to the generic path on mismatch.
- SearchBlock's restored tail file header added a row without consuming a tail
  slot, exceeding maxLines by one and overstating the hidden count. Make it
  consume a slot so the visible count holds at maxLines and `hidden` stays exact.

Correct the fixture JSDoc (now genuinely exceeds the row cap) and the Agent Note
recovery-text claim, sync the ui-conversation bilingual README with the search
row, and add an assembled keyless snapshot (apps/web/tests/search-card.snapshot.ts)
that pins the grep card's shape from the built bundles.

apps/web/tests/snapshots/search-card/grep-card.expected.txt

@@ -0,0 +1,11 @@
+kind=matches
+summary=显示 9 / 共 42 处匹配 · 3 个文件
+file=packages/client/ui-primitives/src/SearchBlock.tsx3
+file=packages/client/ui-conversation/src/client/toolviews/search-row.tsx4
+line=16: export const DEFAULT_SEARCH_MAX_LINES = 16
+line=138: export function SearchBlock(props: SearchBlockProps) {
+line=141:   const [collapsed, setCollapsed] = useState<ReadonlySet<number>>(() => new Set())
+line=73:   const search = searchCardModel(block)
+line=90:         <SearchBlock {...search.card} maxLines={CHAT_SEARCH_MAX_LINES} className={css.search} />
+line=113:     ctx.slots.register({ name: 'conversation.chat.toolview', key: 'grep' }, SearchRow)
+expand=… 其余 4 行