feat(buddy): 为对话模式补充分支能力

.playwright/scripts/__tests__/conversation-canvas.e2e.mjs

@@ -4,6 +4,7 @@ import { expect, test } from '../fixtures/electron.mjs'
 async function prepare(buddy, label) {
   const instance = await buddy.createInstance(label)
   const desktop = await instance.launch()
+  await expect.poll(async () => (await desktop.page.evaluate(() => window.lexoraDesktop.localChat.runtime.getStatus())).status).toBe('ready')
   await desktop.app.evaluate(({ BrowserWindow, ipcMain }, databasePath) => {
     BrowserWindow.getAllWindows()[0].setSize(2000, 1100)
     const { DatabaseSync } = process.getBuiltinModule('node:sqlite')
@@ -72,6 +73,7 @@ test('canvas actions, zoom and node lifetimes stay scoped across split panes and
   await first.getByTestId('conversation-canvas-toggle').click()
   await expect(first.locator('.conversation-node')).toHaveCount(1)
   await first.getByTestId('pane-layout-menu').click()
+  await page.locator('.n-dropdown-menu:visible').getByText('分屏', { exact: true }).hover()
   await page.locator('.n-dropdown-menu:visible').getByText('向右分屏', { exact: true }).click()
   await task(page, 'b').click()
   const second = pane(page, 'Canvas B')

apps/buddy/src/i18n/locales/en-US/chat.ts

@@ -63,7 +63,6 @@ export default {
   'desktop.canvas.failed': 'Failed',
   'desktop.canvas.cancelled': 'Stopped',
   'desktop.canvas.completed': 'Completed',
-  'desktop.canvas.followup': 'Follow up on this answer',
   'desktop.canvas.retry': 'Regenerate answer',
   'desktop.canvas.writeInComposer': 'Continue in the composer',
   'desktop.canvas.generating': 'Generating an answer…',
@@ -77,8 +76,6 @@ export default {
   'desktop.canvas.resetZoom': 'Reset zoom to 100%',
   'desktop.canvas.loading': 'Loading canvas…',
   'desktop.canvas.reload': 'Reload',
-  'desktop.canvas.composerTarget': 'Following up on this answer',
-  'desktop.canvas.cancelFollowup': 'Back to current branch',
   'activity.status.completed': 'Completed',
   'activity.status.failed': 'Failed',
   'activity.status.running': 'Running',
@@ -318,6 +315,15 @@ export default {
   'desktop.chat.runtimeRestart': 'Restart',
   'desktop.chat.runtimeStarting': 'Starting local runtime',
   'desktop.chat.regenerate': 'Regenerate',
+  'desktop.chat.followup': 'Branch from here',
+  'desktop.chat.followupTarget': 'Branch from this answer',
+  'desktop.chat.followupHint': 'Use the conversation up to this answer only. Sending creates a new branch and keeps the original conversation.',
+  'desktop.chat.followupSource': 'Selected answer',
+  'desktop.chat.locateFollowup': 'View origin',
+  'desktop.chat.cancelFollowup': 'Cancel branch',
+  'desktop.chat.cancelFollowupHint': 'Return to the current branch and keep this follow-up draft.',
+  'desktop.chat.branchPosition': 'Branch {index} / {count}',
+  'desktop.chat.branchNavigationHint': 'Switch the conversation after this point. Other branches are kept.',
   'desktop.chat.nextBranch': 'Next branch',
   'desktop.chat.previousBranch': 'Previous branch',
   'desktop.chat.editingHistoryMessage': 'Editing a historical message',

apps/buddy/src/i18n/locales/zh-CN/chat.ts

@@ -61,7 +61,6 @@ export default {
   'desktop.canvas.failed': '失败',
   'desktop.canvas.cancelled': '已停止',
   'desktop.canvas.completed': '已完成',
-  'desktop.canvas.followup': '从这条回答追问',
   'desktop.canvas.retry': '重新生成回答',
   'desktop.canvas.writeInComposer': '在输入框继续提问',
   'desktop.canvas.generating': '正在生成回答…',
@@ -75,8 +74,6 @@ export default {
   'desktop.canvas.resetZoom': '恢复 100% 缩放',
   'desktop.canvas.loading': '正在读取画布…',
   'desktop.canvas.reload': '重新加载',
-  'desktop.canvas.composerTarget': '正在这条回答后追问',
-  'desktop.canvas.cancelFollowup': '返回当前分支',
   'activity.status.completed': '完成',
   'activity.status.failed': '失败',
   'activity.status.running': '进行中',
@@ -316,6 +313,15 @@ export default {
   'desktop.chat.runtimeRestart': '重新启动',
   'desktop.chat.runtimeStarting': '正在启动本地运行时',
   'desktop.chat.regenerate': '重新生成',
+  'desktop.chat.followup': '从这里分支',
+  'desktop.chat.followupTarget': '从这条回答创建分支',
+  'desktop.chat.followupHint': '只沿用到这条回答为止的对话。发送后创建新分支，原对话保留。',
+  'desktop.chat.followupSource': '所选回答',
+  'desktop.chat.locateFollowup': '查看起点',
+  'desktop.chat.cancelFollowup': '取消分支',
+  'desktop.chat.cancelFollowupHint': '返回当前分支，保留这份追问草稿。',
+  'desktop.chat.branchPosition': '分支 {index} / {count}',
+  'desktop.chat.branchNavigationHint': '切换此处之后的对话，其他分支仍会保留。',
   'desktop.chat.nextBranch': '下一条分支',
   'desktop.chat.previousBranch': '上一条分支',
   'desktop.chat.editingHistoryMessage': '正在编辑历史消息',

apps/buddy/src/modules/tasks/model/canvas/conversationCanvasLayout.ts

@@ -1,7 +1,10 @@
 import type { LocalConversationTreeNode } from '@buddy-shared/conversation/conversationTree'
 
 export type ConversationCanvasDirection = 'horizontal' | 'vertical'
-export type ConversationCanvasNode = Omit<LocalConversationTreeNode, 'kind'> & { kind: LocalConversationTreeNode['kind'] | 'draft' }
+export type ConversationCanvasNode = Omit<LocalConversationTreeNode, 'kind'> & {
+  kind: LocalConversationTreeNode['kind'] | 'draft'
+  canFollowup?: boolean
+}
 export interface ConversationNodePosition { x: number, y: number, width: number, height: number }
 
 export function layoutConversationCanvas(nodes: readonly ConversationCanvasNode[], direction: ConversationCanvasDirection): ReadonlyMap<string, ConversationNodePosition> {

apps/buddy/src/modules/tasks/model/transcript/__tests__/chatMessageActions.spec.ts

@@ -0,0 +1,117 @@
+import type { ChatTranscriptMessageRow, ChatTranscriptTurnResultRow } from '../chatTranscriptTypes'
+import { describe, expect, it } from 'vitest'
+import { getChatMessageFollowupSourceId, projectChatAgentTurnActions, projectChatFollowupMessageIds, projectChatMessageActions } from '../chatMessageActions'
+
+function reply(id: string, runId: string, patch: Partial<ChatTranscriptMessageRow> = {}): ChatTranscriptMessageRow {
+  return {
+    key: id,
+    kind: 'message',
+    message: {
+      id,
+      runId,
+      role: 'assistant',
+      branchId: 'branch',
+      conversationId: 'conversation',
+      attachments: [],
+      content: { text: id },
+      createdAt: '2026-09-08T00:00:00.000Z',
+    },
+    turnOutputs: null,
+    ...patch,
+  }
+}
+
+function question(id: string): ChatTranscriptMessageRow {
+  const row = reply(id, 'unused')
+  return { ...row, message: { ...row.message, role: 'user', runId: null } }
+}
+
+function result(runId: string, finalMessageId: string): ChatTranscriptTurnResultRow {
+  return {
+    key: `result-${runId}`,
+    kind: 'turn-result',
+    turn: {
+      branchId: 'branch',
+      completedAt: '2026-09-08T00:00:01.000Z',
+      finalMessageId,
+      nodes: [],
+      processMessageIds: [],
+      progress: null,
+      reasoningLevel: null,
+      runId,
+      startedAt: '2026-09-08T00:00:00.000Z',
+      status: 'completed',
+      triggeringMessageId: 'question',
+      usage: null,
+    },
+  }
+}
+
+describe('chat turn branch origins', () => {
+  it('offers history branching only after another public message, not for the current turn or trailing result metadata', () => {
+    const outcome = result('root', 'final')
+    const source = reply('final', 'root', { turnResult: outcome.turn })
+    const completed = new Set(['root'])
+    expect([...projectChatFollowupMessageIds([source], completed)]).toEqual([])
+    expect([...projectChatFollowupMessageIds([reply('final', 'root'), outcome], completed)]).toEqual([])
+    expect([...projectChatFollowupMessageIds([source, question('next')], completed)]).toEqual(['final'])
+    expect(projectChatAgentTurnActions(outcome.turn, false, true).showFollowup).toBe(false)
+    expect(projectChatAgentTurnActions(outcome.turn, false, true, true).showFollowup).toBe(true)
+  })
+
+  it('keeps branching at the root result even when the toolbar is presented on a partner reply', () => {
+    const firstPartner = reply('first-partner-reply', 'first-partner')
+    const finalPartner = reply('last-partner-reply', 'last-partner', { turnResult: result('root', 'root-final').turn })
+    const completed = new Set(['root', 'first-partner', 'last-partner'])
+    expect([...projectChatFollowupMessageIds([firstPartner, finalPartner], completed)]).toEqual([])
+    expect([...projectChatFollowupMessageIds([firstPartner, finalPartner, question('next')], completed)]).toEqual(['root-final'])
+    expect(getChatMessageFollowupSourceId(firstPartner)).toBeNull()
+    expect(getChatMessageFollowupSourceId(finalPartner)).toBe('root-final')
+    expect(projectChatMessageActions(firstPartner.message, false, false, true)).toMatchObject({
+      showCopy: true,
+      showTime: true,
+      showRegenerate: false,
+      showFollowup: false,
+    })
+    expect(projectChatMessageActions(finalPartner.message, false, true, true)).toMatchObject({
+      showRegenerate: true,
+      showFollowup: true,
+    })
+  })
+
+  it('keeps independent root turns separate while ignoring completed partner replies', () => {
+    const rows = [
+      reply('root-final', 'root', { turnResult: result('root', 'root-final').turn }),
+      reply('partner-final', 'partner'),
+      question('second-question'),
+      reply('second-final', 'second', { turnResult: result('second', 'second-final').turn }),
+      question('next'),
+    ]
+    expect([...projectChatFollowupMessageIds(rows, new Set(['root', 'second', 'partner']))]).toEqual(['root-final', 'second-final'])
+  })
+
+  it('preserves a historical completed result without a visible body, using its own final message as the source', () => {
+    const outcome = result('root', 'empty-root-final')
+    const partner = reply('partner-final', 'partner')
+    expect([...projectChatFollowupMessageIds([partner, outcome], new Set(['root', 'partner']))]).toEqual([])
+    expect([...projectChatFollowupMessageIds([partner, outcome, question('next')], new Set(['root', 'partner']))]).toEqual(['empty-root-final'])
+  })
+
+  it.each([
+    { streaming: true as const },
+    { isIntermediate: true as const },
+    { showActions: false as const },
+  ])('does not branch from an unfinished or hidden result: %j', (patch) => {
+    expect([...projectChatFollowupMessageIds([
+      reply('last', 'root', { turnResult: result('root', 'last').turn, ...patch }),
+      question('next'),
+    ], new Set(['root']))]).toEqual([])
+  })
+
+  it('keeps turn controls disabled during mutation and excludes messages without an execution', () => {
+    const message = reply('final', 'root').message
+    expect(projectChatMessageActions(message, true, true, true)).toMatchObject({ disabled: true, showFollowup: true })
+    expect(projectChatMessageActions({ ...message, runId: null }, false, true, true).showFollowup).toBe(false)
+    expect(projectChatMessageActions({ ...message, role: 'user' }, false, true, true).showFollowup).toBe(false)
+  })
+})

apps/buddy/src/modules/tasks/model/transcript/__tests__/chatMessageBranches.spec.ts

@@ -134,8 +134,8 @@ describe('projectChatMessageBranchNavigators', () => {
       nextBranchId: 'branch-retry',
       previousBranchId: null,
     })
-    expect(projectChatAgentTurnActions(turn, false, true)).toEqual({ disabled: false, showCopy: status !== 'completed', showEdit: false, showRegenerate: true, showTime: true })
-    expect(projectChatAgentTurnActions(turn, false, false)).toEqual({ disabled: false, showCopy: false, showEdit: false, showRegenerate: false, showTime: false })
+    expect(projectChatAgentTurnActions(turn, false, true, true)).toEqual({ disabled: false, showCopy: status !== 'completed', showEdit: false, showFollowup: status === 'completed', showRegenerate: true, showTime: true })
+    expect(projectChatAgentTurnActions(turn, false, false)).toEqual({ disabled: false, showCopy: false, showEdit: false, showFollowup: false, showRegenerate: false, showTime: false })
   })
 
   it('attaches edited user-input siblings to the edited user message', () => {

apps/buddy/src/modules/tasks/model/transcript/chatMessageActions.ts

@@ -1,25 +1,67 @@
 import type { LocalMessage } from '@buddy-shared/conversation/conversationApi'
 
 import type { ChatAgentTurn } from './chatAgentTurn'
+import type { ChatTranscriptMessageRow, ChatTranscriptRow } from './chatTranscriptTypes'
 
 export interface ChatMessageActions {
   disabled: boolean
   showCopy: boolean
   showEdit: boolean
+  showFollowup: boolean
   showRegenerate: boolean
   showTime: boolean
 }
 
+export function getChatMessageFollowupSourceId(row: Pick<ChatTranscriptMessageRow, 'message' | 'turnResult'> & { ownsResultActions?: boolean }): string | null {
+  return row.turnResult?.finalMessageId ?? (row.ownsResultActions ? row.message.id : null)
+}
+
+export function projectChatFollowupMessageIds(
+  rows: readonly ChatTranscriptRow[],
+  completedRunIds: ReadonlySet<string>,
+): ReadonlySet<string> {
+  const finalMessages = new Map<string, { messageId: string, index: number, available: boolean }>()
+  let lastMessageIndex = -1
+  for (const [index, row] of rows.entries()) {
+    if (row.kind === 'message' && (row.message.role === 'user' || row.message.role === 'assistant')) {
+      lastMessageIndex = index
+      const messageId = getChatMessageFollowupSourceId(row)
+      const runId = row.turnResult?.runId ?? row.message.runId
+      if (row.message.role === 'assistant' && messageId && runId) {
+        finalMessages.set(runId, {
+          messageId,
+          index,
+          available: !row.streaming && !row.isIntermediate && row.showActions !== false,
+        })
+      }
+    }
+    else if ((row.kind === 'turn-result' || (row.kind === 'agent-turn' && row.ownsResultActions)) && row.turn.finalMessageId) {
+      finalMessages.set(row.turn.runId, {
+        messageId: row.turn.finalMessageId,
+        index,
+        available: row.turn.status === 'completed',
+      })
+    }
+  }
+  return new Set([...finalMessages].flatMap(([runId, source]) =>
+    completedRunIds.has(runId) && source.available && source.index < lastMessageIndex
+      ? [source.messageId]
+      : [],
+  ))
+}
+
 export function projectChatMessageActions(
   message: LocalMessage,
   disabled: boolean,
   ownsResultActions: boolean,
+  canFollowup = false,
 ): ChatMessageActions {
   const lifecycleMessage = message.role === 'user' || message.role === 'assistant'
   return {
     disabled,
     showCopy: lifecycleMessage,
     showEdit: message.role === 'user',
+    showFollowup: ownsResultActions && canFollowup && message.role === 'assistant' && message.runId !== null,
     showRegenerate: ownsResultActions && message.role === 'assistant' && message.runId !== null,
     showTime: lifecycleMessage,
   }
@@ -29,13 +71,15 @@ export function projectChatAgentTurnActions(
   turn: ChatAgentTurn,
   disabled: boolean,
   ownsResultActions: boolean,
+  canFollowup = false,
 ): ChatMessageActions {
   const showActions = ownsResultActions
     && (turn.status === 'completed' || turn.status === 'failed' || turn.status === 'cancelled')
   return {
     disabled,
     showCopy: showActions && turn.status !== 'completed',
     showEdit: false,
+    showFollowup: canFollowup && showActions && turn.status === 'completed' && turn.finalMessageId !== null,
     showRegenerate: showActions,
     showTime: showActions,
   }

apps/buddy/src/modules/tasks/widgets/canvas/ConversationMessageNode.vue

@@ -1,8 +1,9 @@
 <script setup lang="ts">
 import type { Node } from '@antv/x6'
 import type { ConversationCanvasData } from './conversationCanvasContext'
-import { Add20Regular, ArrowSync20Regular, Document20Regular, Keyboard20Regular, Wand20Regular } from '@vicons/fluent'
+import { Document20Regular, Keyboard20Regular, Wand20Regular } from '@vicons/fluent'
 import { useIntervalFn } from '@vueuse/core'
+import { NTooltip } from 'naive-ui'
 import { computed, inject, onBeforeUnmount, shallowRef, useTemplateRef, watch } from 'vue'
 import { useBuddyI18n } from '@/i18n/buddyI18n'
 import DesktopIcon from '@/shared/ui/icon/DesktopIcon.vue'
@@ -74,22 +75,37 @@ function open(event: MouseEvent) {
   >
     <div class="conversation-node__card" :class="{ 'buddy-border-beam': message.status === 'running' }">
       <header class="conversation-node__header">
-        <DesktopIcon class="conversation-node__role" :component="message.kind === 'answer' ? Wand20Regular : Keyboard20Regular" :title="label" />
+        <DesktopIcon class="conversation-node__role" :component="message.kind === 'answer' ? Wand20Regular : Keyboard20Regular" />
         <span v-if="message.toolCount" class="conversation-node__tools">{{ t('desktop.canvas.tools', { count: message.toolCount }) }}</span>
         <div class="conversation-node__trailing flex flex-none items-center gap-[6px] ml-auto">
           <span v-if="message.kind === 'draft'" class="conversation-node__status">{{ label }}</span>
           <span v-if="message.status && message.status !== 'completed'" class="conversation-node__status" :class="message.status">{{ t(`desktop.canvas.${message.status}`) }}</span>
           <div v-if="!simplified && message.kind !== 'draft' && !busy" class="conversation-node__actions" role="toolbar" :aria-label="t('desktop.canvas.nodeActions')" @pointerdown.stop @mousedown.stop>
-            <button v-if="message.kind === 'question'" type="button" :disabled="!data.canMutate" :aria-label="t('desktop.chat.editMessage')" :title="t('desktop.chat.editMessage')" data-testid="canvas-node-edit" @click.stop="actions.edit(message.id)">
-              <DesktopIcon name="edit" />
-            </button>
+            <NTooltip v-if="message.kind === 'question'" placement="top">
+              <template #trigger>
+                <button type="button" :disabled="!data.canMutate" :aria-label="t('desktop.chat.editMessage')" data-testid="canvas-node-edit" @click.stop="actions.edit(message.id)">
+                  <DesktopIcon name="edit" />
+                </button>
+              </template>
+              {{ t('desktop.chat.editMessage') }}
+            </NTooltip>
             <template v-else>
-              <button type="button" :disabled="!data.canMutate" :aria-label="t('desktop.canvas.retry')" :title="t('desktop.canvas.retry')" data-testid="canvas-node-retry" @click.stop="actions.retry(message.id)">
-                <DesktopIcon :component="ArrowSync20Regular" />
-              </button>
-              <button v-if="message.status === 'completed'" type="button" :disabled="!data.canMutate" :aria-label="t('desktop.canvas.followup')" :title="t('desktop.canvas.followup')" data-testid="canvas-node-followup" @click.stop="actions.followup(message.id)">
-                <DesktopIcon :component="Add20Regular" />
-              </button>
+              <NTooltip placement="top">
+                <template #trigger>
+                  <button type="button" :disabled="!data.canMutate" :aria-label="t('desktop.canvas.retry')" data-testid="canvas-node-retry" @click.stop="actions.retry(message.id)">
+                    <DesktopIcon name="messageRetry" />
+                  </button>
+                </template>
+                {{ t('desktop.canvas.retry') }}
+              </NTooltip>
+              <NTooltip v-if="message.status === 'completed' && message.messageId && message.canFollowup !== false" placement="top">
+                <template #trigger>
+                  <button type="button" :disabled="!data.canMutate" :aria-label="t('desktop.chat.followup')" data-testid="canvas-node-followup" @click.stop="actions.followup(message.id)">
+                    <DesktopIcon name="messageBranch" />
+                  </button>
+                </template>
+                {{ t('desktop.chat.followup') }}
+              </NTooltip>
             </template>
           </div>
         </div>