perf(tool): retain unchanged subcall branches

packages/client/ui-tool/README.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write packages/client/ui-tool/README.md
-README.md: 8f0dfd0bc0222bb6ea428deb0dd6769f7347e41c
-README.zh.md: bd4681022f1215a3e0dcda48b73c911b5bc6a283
+README.md: 39b05236deae913d8be31be7846cac6f853b7eca
+README.zh.md: e06ec350ad299593c82a216949fcdfa713122387

packages/client/ui-tool/README.md

@@ -63,7 +63,7 @@ The package realizes one dispatch rule: atomic Tool views are keyed by wire Tool
 
 ### Rendering contract
 
-`ToolCallTree` receives one Tool node, Session `cwd`, and navigation callbacks. It derives explicit phase props from the root and dispatches each tool by name through `tool.call.toolview`. Dispatched roots retain their recursive `subCalls`; preparation has no children. Each root and child wrapper preserves the `data-chat-anchor-key="call:<id>"` and `data-chat-call-id` DOM contract used for paging and selection. The Tool node keeps the same callId across all three stages.
+`ToolCallTree` receives one Tool node, Session `cwd`, and navigation callbacks. Each branch receives a stable block and memoizes its explicit phase props, so changing one subcall leaves unchanged sibling branches unrendered. It dispatches each tool by name through `tool.call.toolview`. Dispatched roots retain their recursive `subCalls`; preparation has no children. Each root and child wrapper preserves the `data-chat-anchor-key="call:<id>"` and `data-chat-call-id` DOM contract used for paging and selection. The Tool node keeps the same callId across all three stages.
 
 Tool owner props forward Chat's stable `useDisclosure` Hook through root and nested calls. Rows invoke it where they own their expanded bodies; intermediate renderers do not subscribe. Each invocation has independent open state that resets when the enclosing Turn collapses, without replacing React identity. Presentation-mode switches preserve it.
 

packages/client/ui-tool/README.zh.md

@@ -63,7 +63,7 @@ owner 载荷为 `ToolCallOwnerProps`：`callId`、`toolName`、冻结的 `block`
 
 ### 渲染约定
 
-`ToolCallTree` 接收一个 Tool 节点、会话 `cwd` 和导航回调。它从根调用数据生成显式阶段 props，并通过 `tool.call.toolview` 按工具名分发。已派发的根调用保留递归 `subCalls`，准备阶段没有子调用。每个根调用和子调用包装层都保留 `data-chat-anchor-key="call:<id>"` 与 `data-chat-call-id` DOM 约定，供分页和选择使用。Tool 节点在三个阶段保持同一个 callId。
+`ToolCallTree` 接收一个 Tool 节点、会话 `cwd` 和导航回调。每个分支接收稳定的 block，并缓存显式阶段 props，因此一个子调用变化不会重渲染未变化的兄弟分支。它通过 `tool.call.toolview` 按工具名分发。已派发的根调用保留递归 `subCalls`，准备阶段没有子调用。每个根调用和子调用包装层都保留 `data-chat-anchor-key="call:<id>"` 与 `data-chat-call-id` DOM 约定，供分页和选择使用。Tool 节点在三个阶段保持同一个 callId。
 
 Tool 所有者属性将 Chat 注入的稳定 `useDisclosure` 钩子传给根调用及嵌套调用。工具行在拥有展开正文的位置调用它，中间 renderer 不订阅。每次调用拥有独立展开状态，外层轮次收起时重置该状态，不替换 React 身份；展示模式切换保留该状态。
 

packages/client/ui-tool/src/client/tool/ToolCallTree.tsx

@@ -59,11 +59,12 @@ const ToolCall = memo(function ToolCall({
 })
 
 const ToolCallBranch = memo(function ToolCallBranch({
-  renderSlot, call, cwd, home, openFile, inspectCall, loadImage, useDisclosure, t,
+  renderSlot, block, cwd, home, openFile, inspectCall, loadImage, useDisclosure, t,
 }: Pick<ToolTreeProps, 'renderSlot' | 'cwd' | 'openFile' | 'inspectCall' | 'loadImage' | 'useDisclosure' | 't'> & {
-  call: ToolCallPhaseProps
+  block: ToolCallBlock
   home?: string | undefined
 }) {
+  const call = useMemo(() => toolCallPhase(block), [block])
   return (
     <ToolCall
       renderSlot={renderSlot}
@@ -84,7 +85,7 @@ const ToolCallBranch = memo(function ToolCallBranch({
             <ToolCallBranch
               key={child.callId}
               renderSlot={renderSlot}
-              call={toolCallPhase(child)}
+              block={child}
               cwd={cwd}
               home={home}
               openFile={openFile}
@@ -110,11 +111,10 @@ export function ToolCallTree({
   renderSlot, node, cwd, openFile, inspectCall, loadImage, useDisclosure, useHostInfo, t,
 }: ToolTreeProps) {
   const home = useHostInfo(info => info.home)
-  const call = useMemo(() => toolCallPhase(node.data.root), [node.data.root])
   return (
     <ToolCallBranch
       renderSlot={renderSlot}
-      call={call}
+      block={node.data.root}
       cwd={cwd}
       home={home}
       openFile={openFile}

packages/client/ui-tool/tests/tool-call-tree.client.spec.tsx

@@ -61,6 +61,20 @@ function props(
 }
 
 describe('ToolCallTree', () => {
+  it('dispatches only the parent and changed child among 100 sibling calls', () => {
+    const children = Array.from({ length: 100 }, (_, index) => root(`child-${index}`, { name: 'custom_child', argsRaw: '{}' }))
+    const block = { ...root('parent', { name: 'custom_parent', argsRaw: '{}' }), subCalls: children }
+    const owners: ToolCallOwnerProps[] = []
+    const initial = props(block, undefined, owners)
+    const view = render(<ToolCallTree {...initial} />)
+    expect(owners).toHaveLength(101)
+    owners.length = 0
+    const changed = { ...children[42]!, isError: true }
+    const next = { ...block, subCalls: children.map((child, index) => index === 42 ? changed : child) }
+    view.rerender(<ToolCallTree {...initial} node={{ ...initial.node, data: { root: next } }} />)
+    expect(owners.map(owner => owner.callId)).toEqual(['parent', 'child-42'])
+  })
+
   it('dispatches preparation through the existing keyed toolview with no argument fields', () => {
     const owners: ToolCallOwnerProps[] = []
     const view = render(<ToolCallTree {...props({