feat(web): render read tool output as a line-numbered code card

Consume the card:'read' result view (path, numbered lines, totalLines, lang)
the read backend PR added. ReadBlock (ui-primitives) draws a per-line gutter
with each line's own file number, shiki highlighting via a new highlightLines
returning per-line token arrays, a 显示 X / Y 行 window note, a height cap
matching TerminalBlock, and a copy control. read-card-model is the single
resultView derivation; a keyed ReadRow registers under read with the card
resident under its path-link summary. The generic fallback and the details
panel are read-aware. Fixture gains a windowed read turn for the built-boot
snapshot.

packages/client/ui-primitives/src/index.ts

@@ -22,6 +22,8 @@ export { JsonTree } from './JsonTree.tsx'
 export type { JsonTreeProps } from './JsonTree.tsx'
 export { TerminalBlock, DEFAULT_TERMINAL_MAX_LINES } from './TerminalBlock.tsx'
 export type { TerminalBlockProps } from './TerminalBlock.tsx'
+export { ReadBlock, DEFAULT_READ_MAX_LINES } from './ReadBlock.tsx'
+export type { ReadBlockProps, ReadBlockLine } from './ReadBlock.tsx'
 export { CodeBlock } from './markdown/CodeBlock.tsx'
 export { JsonBlock } from './markdown/JsonBlock.tsx'
 export { MarkdownText } from './markdown/MarkdownText.tsx'