fix(fs): validate read meta semantics and sync public result-view docs

readMetaFromMeta narrows the opaque persisted meta boundary, so beyond
shape it now rejects replayed JSON that is well-typed but semantically
invalid: line numbers must be 1-based integers, totalLines a non-negative
integer, and line numbers must strictly increase without exceeding
totalLines. Any violation declines to the generic fallback.

Sync the public ToolResultView contract across the core/tools and
tool-fs READMEs and docs/core-data-structures/tools for the fourth
result-view member and the ReadFileLine vocabulary, and expand the
Agent Note Testing section with the new rejection paths and the snapshot
evidence this PR carries.

packages/core/tools/README.zh.md

@@ -108,7 +108,7 @@ ctx.tools.register(defineTool({
 工具可以选择拥有纯 `presentCall()` 和 `presentResult()` 呈现意图，使 UI 无需特殊处理工具名称：
 
 - 调用视图为 `{ card: 'generic', title, kind?, rawInput?, content?, locations? }`、`{ card: 'terminal', title, description?, cwd? }` 或 `{ card: 'diff', title, diffs, locations? }`。
-- 结果视图为 `{ card: 'generic', title?, content? }`、`{ card: 'terminal', title?, output?, exitCode?, signal? }` 或 `{ card: 'diff', title?, diffs }`。
+- 结果视图为 `{ card: 'generic', title?, content? }`、`{ card: 'terminal', title?, output?, exitCode?, signal? }`、`{ card: 'diff', title?, diffs }` 或 `{ card: 'read', title?, path, lines, totalLines, lang?, content? }`（已完成的文件读取→带行号、可选语法高亮的代码视图；`lines` 是 `{ number, text }[]`，保留每一行的文件行号，`content` 是无读取能力的 UI 回退时使用的去信封文本）。
 
 返回 `undefined` 会选择通用回退。呈现器只依赖其参数和持久结果，因为 UI 会在实时流式输出和日志回放期间调用它们。`output.presentationMeta(args, value)` 为直接接口调用派生 JSON 元数据；该元数据随 `tool/result` 持久化并传回 `presentResult`，而规范值本身仍只存在于执行局部，绝不会回放。嵌套 Code 分发不会计算元数据。`defineTool` 会软验证较旧的日志参数并回退，而不会使回放崩溃。`dsh-tool-bash` 与 `dsh-tool-fs` 是参考实现；[规范输出 Agent Note](../../../.agents/notes/implemented/architecture/2026-07-20-canonical-tool-output-contract.md) 规定值／呈现拆分，[呈现意图 Agent Note](../../../.agents/notes/implemented/architecture/2026-07-02-tool-render-intent-union.md) 规定卡片词汇。