refactor(fs): minimize and cap search card meta; keep TUI byte-identical

Address the review of the search render card:

- The search result view carries no `content`: it was a no-op for every
  consumer and serialized the whole search text twice. A UI without a search
  card falls back to the raw tool/result content; the TUI stays byte-identical
  to the pre-search-card generic fallback.
- Bound the serialized presentationMeta with a configurable searchMetaMaxBytes
  (default 64 KiB): the inline item cap does not bound bytes, and spill-policy
  only shrinks content, never meta. capMetaBytes drops trailing groups/paths.
- Share one retention pass (retainGrepMatches/retainGlobPaths in search-core)
  between the model-facing render and the meta projection; remove the second
  cap/preview implementation and the presentation<->grep module cycle by
  moving GrepMatch/previewLine to search-core.
- Rename the result-view discriminant kind -> shape so it no longer collides
  with GenericCallView.kind (ToolCallKind, whose values include 'search').
- Narrow the entry export surface to consumed symbols.
- Sync the three bilingual ToolResultView doc pairs and the Agent Note pair;
  document the deliberate empty-card acceptance vs diffsFromMeta.
- Regenerate config/tool/cordis catalogs for the new config field.

docs/core-data-structures/tools.zh.md

@@ -447,7 +447,7 @@ type ObjectJsonSchema = JsonSchemaNode & { type: 'object' }
 工具希望其调用在 UI 中如何呈现（编辑器工具调用卡片、CLI（命令行界面）日志行），提供方无关，使工具在不依赖任何客户端协议的情况下描述自身。`presentCall`/`presentResult` 返回一个 **`card` 标签的渲染意图**——一个可辨识联合类型，UI 桥接层据此分发：
 
 - `ToolCallView`（待执行）：`{ card: 'generic', title, kind?, rawInput?, content?, locations? }`（默认卡片；`locations` 是 `{ path, line? }[]`，表示调用读取/修改的文件，供编辑器跟随）、`{ card: 'terminal', title, description?, cwd? }`（shell 命令→终端卡片）、或 `{ card: 'diff', title, diffs, locations? }`（文件创建/修改→行内 diff 卡片；`diffs` 是 `{ path, oldText, newText }[]`，新文件时 `oldText: null`）。
-- `ToolResultView`（已完成）：`{ card: 'generic', title?, content? }`、`{ card: 'terminal', title?, output?, exitCode?, signal? }`（捕获的运行输出 + 退出状态；有能力的 UI 显示退出状态标签，其他 UI 可以派生围栏 ` ```console ` 回退）、或 `{ card: 'diff', title?, diffs }`（已完成的文件变更→要展示的变更，通常是从变更前后内容计算出带上下文行的已应用 hunk，或在没有前像时的整文件 diff）。已完成视图会替换待执行视图，因此变更工具即使与调用时的片段重复也要返回 diff 结果。
+- `ToolResultView`（已完成）：`{ card: 'generic', title?, content? }`、`{ card: 'terminal', title?, output?, exitCode?, signal? }`（捕获的运行输出 + 退出状态；有能力的 UI 显示退出状态标签，其他 UI 可以派生围栏 ` ```console ` 回退）、`{ card: 'diff', title?, diffs }`（已完成的文件变更→要展示的变更，通常是从变更前后内容计算出带上下文行的已应用 hunk，或在没有前像时的整文件 diff）、或 `{ card: 'search', shape, title?, truncated, total, … }`（已完成的发现型搜索→`shape: 'matches'`（grep）为按文件分组的匹配，`shape: 'paths'`（glob）为扁平路径列表；`truncated`/`total` 报告内联结果是否被截断，使 UI 永不把部分结果当作完整结果呈现；该视图不携带结果文本——无 search 卡片的 UI 回退到原始结果内容）。已完成视图会替换待执行视图，因此变更工具即使与调用时的片段重复也要返回 diff 结果；搜索没有 `card: 'search'` 的调用时对应视图（其 pending 状态保持为 generic 卡片，因为匹配只在 `execute` 之后才存在）。
 
 `ToolCallKind`（`'read' | 'edit' | 'delete' | 'move' | 'search' | 'execute' | 'fetch' | 'other'`）用于为通用卡片选择图标。`FileLocation`（`{ path, line? }`）与 `FileDiff`（`{ path, oldText, newText }`）是共享的文件卡片词汇。该设计由[渲染意图联合类型 Agent Note（agent 决策记录）](../../.agents/notes/implemented/architecture/2026-07-02-tool-render-intent-union.md)固定；TUI 和 host/client 运行时将这套中性词汇投影为各自的视图。