feat: improve application responsiveness

src/main/agent-event-buffer.test.ts

@@ -0,0 +1,177 @@
+import { afterEach, describe, expect, it, vi } from 'vitest'
+import type { AgentEvent } from '../shared/contracts'
+import { AgentEventBuffer } from './agent-event-buffer'
+
+const requestId = '00000000-0000-4000-8000-000000000001'
+
+describe('AgentEventBuffer', () => {
+  afterEach(() => {
+    vi.useRealTimers()
+  })
+
+  it('combines 100 adjacent text deltas into one event', () => {
+    vi.useFakeTimers()
+    const events: AgentEvent[] = []
+    const buffer = new AgentEventBuffer({
+      onEvent: (event) => events.push(event)
+    })
+
+    for (let index = 0; index < 100; index += 1) {
+      buffer.push({ requestId, type: 'text', delta: `${index},` })
+    }
+    expect(events).toEqual([])
+
+    buffer.close()
+    expect(events).toEqual([
+      {
+        requestId,
+        type: 'text',
+        delta: Array.from({ length: 100 }, (_, index) => `${index},`).join(
+          ''
+        )
+      }
+    ])
+  })
+
+  it('preserves text, reasoning, and immediate tool order', () => {
+    vi.useFakeTimers()
+    const events: AgentEvent[] = []
+    const buffer = new AgentEventBuffer({
+      onEvent: (event) => events.push(event)
+    })
+
+    buffer.push({ requestId, type: 'text', delta: 'answer' })
+    buffer.push({ requestId, type: 'reasoning', delta: 'thought' })
+    buffer.push({
+      requestId,
+      type: 'tool',
+      callId: 'call-1',
+      name: 'read',
+      state: 'completed',
+      summary: 'read completed'
+    })
+
+    expect(events.map((event) => event.type)).toEqual([
+      'text',
+      'reasoning',
+      'tool'
+    ])
+  })
+
+  it('flushes before a combined delta exceeds the size bound', () => {
+    vi.useFakeTimers()
+    const events: AgentEvent[] = []
+    const buffer = new AgentEventBuffer({
+      maximumBufferedBytes: 5,
+      onEvent: (event) => events.push(event)
+    })
+
+    buffer.push({ requestId, type: 'text', delta: '123' })
+    buffer.push({ requestId, type: 'text', delta: '456' })
+    expect(events).toEqual([
+      { requestId, type: 'text', delta: '123' }
+    ])
+
+    buffer.close()
+    expect(events).toEqual([
+      { requestId, type: 'text', delta: '123' },
+      { requestId, type: 'text', delta: '456' }
+    ])
+  })
+
+  it('flushes buffered deltas when its timer expires', () => {
+    vi.useFakeTimers()
+    const events: AgentEvent[] = []
+    const buffer = new AgentEventBuffer({
+      flushIntervalMs: 32,
+      onEvent: (event) => events.push(event)
+    })
+
+    buffer.push({ requestId, type: 'reasoning', delta: 'thinking' })
+    vi.advanceTimersByTime(31)
+    expect(events).toEqual([])
+    vi.advanceTimersByTime(1)
+    expect(events).toEqual([
+      { requestId, type: 'reasoning', delta: 'thinking' }
+    ])
+  })
+
+  it('supports frame-paced UI updates with coarser durable writes', () => {
+    vi.useFakeTimers()
+    const publicEvents: AgentEvent[] = []
+    const persistedEvents: AgentEvent[] = []
+    const publicBuffer = new AgentEventBuffer({
+      flushIntervalMs: 16,
+      onEvent: (event) => publicEvents.push(event)
+    })
+    const persistedBuffer = new AgentEventBuffer({
+      flushIntervalMs: 32,
+      onEvent: (event) => persistedEvents.push(event)
+    })
+    const first: AgentEvent = {
+      requestId,
+      type: 'text',
+      delta: 'first'
+    }
+    publicBuffer.push(first)
+    persistedBuffer.push(first)
+
+    vi.advanceTimersByTime(16)
+    expect(publicEvents).toEqual([first])
+    expect(persistedEvents).toEqual([])
+
+    const second: AgentEvent = {
+      requestId,
+      type: 'text',
+      delta: 'second'
+    }
+    publicBuffer.push(second)
+    persistedBuffer.push(second)
+    publicBuffer.close()
+    persistedBuffer.close()
+
+    expect(publicEvents).toEqual([first, second])
+    expect(persistedEvents).toEqual([
+      {
+        requestId,
+        type: 'text',
+        delta: 'firstsecond'
+      }
+    ])
+  })
+
+  it('closes idempotently and ignores events after close', () => {
+    vi.useFakeTimers()
+    const events: AgentEvent[] = []
+    const buffer = new AgentEventBuffer({
+      onEvent: (event) => events.push(event)
+    })
+
+    buffer.push({ requestId, type: 'text', delta: 'once' })
+    buffer.close()
+    buffer.close()
+    buffer.push({ requestId, type: 'text', delta: 'late' })
+    vi.runAllTimers()
+
+    expect(events).toEqual([
+      { requestId, type: 'text', delta: 'once' }
+    ])
+  })
+
+  it('reports timer publication errors instead of throwing asynchronously', () => {
+    vi.useFakeTimers()
+    const error = new Error('database unavailable')
+    const onError = vi.fn()
+    const buffer = new AgentEventBuffer({
+      flushIntervalMs: 32,
+      onError,
+      onEvent: () => {
+        throw error
+      }
+    })
+
+    buffer.push({ requestId, type: 'text', delta: 'pending' })
+    expect(() => vi.advanceTimersByTime(32)).not.toThrow()
+    expect(onError).toHaveBeenCalledWith(error)
+  })
+})

src/main/agent-event-buffer.ts

@@ -0,0 +1,125 @@
+import type { AgentEvent } from '../shared/contracts'
+
+type BufferedAgentEvent = Extract<
+  AgentEvent,
+  { type: 'text' | 'reasoning' }
+>
+
+export type AgentEventBufferOptions = {
+  onEvent(event: AgentEvent): void
+  onError?(error: unknown): void
+  flushIntervalMs?: number
+  maximumBufferedBytes?: number
+}
+
+const DEFAULT_FLUSH_INTERVAL_MS = 32
+const DEFAULT_MAXIMUM_BUFFERED_BYTES = 64 * 1024
+
+export class AgentEventBuffer {
+  private readonly onEvent: (event: AgentEvent) => void
+  private readonly onError: ((error: unknown) => void) | undefined
+  private readonly flushIntervalMs: number
+  private readonly maximumBufferedBytes: number
+  private pending: BufferedAgentEvent | undefined
+  private pendingBytes = 0
+  private timer: ReturnType<typeof setTimeout> | undefined
+  private closed = false
+
+  constructor(options: AgentEventBufferOptions) {
+    this.onEvent = options.onEvent
+    this.onError = options.onError
+    this.flushIntervalMs =
+      options.flushIntervalMs ?? DEFAULT_FLUSH_INTERVAL_MS
+    this.maximumBufferedBytes =
+      options.maximumBufferedBytes ??
+      DEFAULT_MAXIMUM_BUFFERED_BYTES
+    if (this.flushIntervalMs <= 0) {
+      throw new Error('flushIntervalMs must be positive')
+    }
+    if (this.maximumBufferedBytes <= 0) {
+      throw new Error('maximumBufferedBytes must be positive')
+    }
+  }
+
+  push(event: AgentEvent): void {
+    if (this.closed) {
+      return
+    }
+    if (event.type !== 'text' && event.type !== 'reasoning') {
+      this.flush()
+      this.onEvent(event)
+      return
+    }
+
+    const eventBytes = Buffer.byteLength(event.delta)
+    const matchesPending =
+      this.pending?.requestId === event.requestId &&
+      this.pending.type === event.type
+    if (!matchesPending) {
+      this.flush()
+    } else if (
+      this.pendingBytes + eventBytes >
+      this.maximumBufferedBytes
+    ) {
+      this.flush()
+    }
+
+    if (eventBytes > this.maximumBufferedBytes) {
+      this.onEvent(event)
+      return
+    }
+    if (this.pending) {
+      this.pending = {
+        ...this.pending,
+        delta: this.pending.delta + event.delta
+      }
+      this.pendingBytes += eventBytes
+      return
+    }
+
+    this.pending = { ...event }
+    this.pendingBytes = eventBytes
+    this.scheduleFlush()
+  }
+
+  flush(): void {
+    this.clearTimer()
+    const event = this.pending
+    this.pending = undefined
+    this.pendingBytes = 0
+    if (event) {
+      this.onEvent(event)
+    }
+  }
+
+  close(): void {
+    if (this.closed) {
+      return
+    }
+    this.closed = true
+    this.flush()
+  }
+
+  private scheduleFlush(): void {
+    if (this.timer) {
+      return
+    }
+    this.timer = setTimeout(() => {
+      this.timer = undefined
+      try {
+        this.flush()
+      } catch (error) {
+        this.onError?.(error)
+      }
+    }, this.flushIntervalMs)
+    this.timer.unref?.()
+  }
+
+  private clearTimer(): void {
+    if (!this.timer) {
+      return
+    }
+    clearTimeout(this.timer)
+    this.timer = undefined
+  }
+}

src/main/assistant/assistant-database.test.ts

@@ -1386,6 +1386,429 @@ describe('AssistantDatabase', () => {
     database.close()
   })
 
+  it('incrementally saves local changes without replacing unrelated or remote data', async () => {
+    const directory = await mkdtemp(
+      join(tmpdir(), 'goodbuddy-incremental-conversations-')
+    )
+    temporaryDirectories.push(directory)
+    const databasePath = join(directory, 'assistant.sqlite')
+    const database = new AssistantDatabase(databasePath)
+    database.initialize('C:\\Workspace')
+    const project = database.listProjects()[0]!
+    const conversationId =
+      '00000000-0000-4000-8000-000000000501'
+    const unrelatedId =
+      '00000000-0000-4000-8000-000000000502'
+    const streamingMessageId =
+      '00000000-0000-4000-8000-000000000503'
+    const newMessageId =
+      '00000000-0000-4000-8000-000000000504'
+    database.replaceConversations([
+      {
+        id: conversationId,
+        projectId: project.id,
+        title: '增量对话',
+        updatedAt: 1_775_000_000_000,
+        messages: [
+          {
+            id: streamingMessageId,
+            role: 'assistant',
+            content: '生成中',
+            createdAt: 1_775_000_000_001,
+            state: 'streaming',
+            status: '正在生成'
+          }
+        ]
+      },
+      {
+        id: unrelatedId,
+        title: '不相关本地对话',
+        updatedAt: 1_775_000_000_002,
+        messages: []
+      }
+    ])
+    const channelProject = database.ensureChannelProjects(
+      'C:\\Users\\test',
+      channelDefaultProfileId
+    )[0]!
+    const remote = database.getOrCreateRemoteConversation({
+      projectId: channelProject.id,
+      channel: 'weixin',
+      accountId: 'default',
+      externalConversationId: 'incremental-preserved',
+      conversationType: 'direct',
+      title: '保留的远程对话',
+      accountDisplay: '发送者 ****0501'
+    })
+    const raw = new DatabaseSync(databasePath)
+    raw
+      .prepare('UPDATE messages SET request_id = ? WHERE id = ?')
+      .run('preserved-request-id', streamingMessageId)
+    raw.close()
+
+    const save = [
+      {
+        header: {
+          id: conversationId,
+          projectId: project.id,
+          title: '增量对话（已完成）',
+          updatedAt: 1_775_000_001_000
+        },
+        messages: [
+          {
+            id: streamingMessageId,
+            role: 'assistant' as const,
+            content: '生成完成',
+            createdAt: 1_775_000_000_001,
+            state: 'complete' as const,
+            status: '已完成'
+          },
+          {
+            id: newMessageId,
+            role: 'user' as const,
+            content: '继续',
+            createdAt: 1_775_000_001_000,
+            state: 'complete' as const
+          }
+        ]
+      }
+    ]
+    database.saveLocalConversations(save)
+    database.saveLocalConversations(save)
+
+    expect(database.getConversation(conversationId)).toMatchObject({
+      title: '增量对话（已完成）',
+      messages: [
+        {
+          id: streamingMessageId,
+          content: '生成完成',
+          state: 'complete',
+          status: '已完成'
+        },
+        {
+          id: newMessageId,
+          content: '继续',
+          state: 'complete'
+        }
+      ]
+    })
+    expect(database.getConversation(unrelatedId).title).toBe(
+      '不相关本地对话'
+    )
+    expect(database.getConversation(remote.id).remote?.channel).toBe(
+      'weixin'
+    )
+
+    const durable = new DatabaseSync(databasePath)
+    expect(
+      durable
+        .prepare(
+          `SELECT id, sequence, request_id
+           FROM messages
+           WHERE conversation_id = ?
+           ORDER BY sequence`
+        )
+        .all(conversationId)
+    ).toEqual([
+      {
+        id: streamingMessageId,
+        sequence: 0,
+        request_id: 'preserved-request-id'
+      },
+      {
+        id: newMessageId,
+        sequence: 1,
+        request_id: null
+      }
+    ])
+    durable.close()
+    database.close()
+  })
+
+  it('keeps incremental local conversation storage bounded to 500 messages', async () => {
+    const directory = await mkdtemp(
+      join(tmpdir(), 'goodbuddy-bounded-local-conversation-')
+    )
+    temporaryDirectories.push(directory)
+    const databasePath = join(directory, 'assistant.sqlite')
+    const database = new AssistantDatabase(databasePath)
+    database.initialize('C:\\Workspace')
+    const project = database.listProjects()[0]!
+    const conversationId =
+      '00000000-0000-4000-8000-000000000521'
+    const messageId = (index: number): string =>
+      `00000000-0000-4000-8001-${String(index).padStart(12, '0')}`
+    database.replaceConversations([
+      {
+        id: conversationId,
+        projectId: project.id,
+        title: '有界增量对话',
+        updatedAt: 1_775_000_000_000,
+        messages: Array.from({ length: 500 }, (_, index) => ({
+          id: messageId(index),
+          role: index % 2 === 0 ? 'user' as const : 'assistant' as const,
+          content: `消息 ${index}`,
+          createdAt: 1_775_000_000_000 + index,
+          state: 'complete' as const
+        }))
+      }
+    ])
+
+    const newestMessageId = messageId(500)
+    database.saveLocalConversations([
+      {
+        header: {
+          id: conversationId,
+          projectId: project.id,
+          title: '有界增量对话',
+          updatedAt: 1_775_000_001_000
+        },
+        messages: [
+          {
+            id: newestMessageId,
+            role: 'user',
+            content: '最新消息',
+            createdAt: 1_775_000_001_000,
+            state: 'complete'
+          }
+        ]
+      }
+    ])
+
+    const restored = database.getConversation(conversationId)
+    expect(restored.messages).toHaveLength(500)
+    expect(restored.messages[0]?.id).toBe(messageId(1))
+    expect(restored.messages.at(-1)?.id).toBe(newestMessageId)
+    const raw = new DatabaseSync(databasePath)
+    expect(
+      raw
+        .prepare(
+          `SELECT COUNT(*) AS count, MIN(sequence) AS minimum,
+                  MAX(sequence) AS maximum
+           FROM messages
+           WHERE conversation_id = ?`
+        )
+        .get(conversationId)
+    ).toEqual({
+      count: 500,
+      minimum: 1,
+      maximum: 500
+    })
+    raw.close()
+    database.close()
+  })
+
+  it('rolls back incremental saves when message ownership or role changes', async () => {
+    const database = await createDatabase()
+    const firstConversationId =
+      '00000000-0000-4000-8000-000000000511'
+    const secondConversationId =
+      '00000000-0000-4000-8000-000000000512'
+    const firstMessageId =
+      '00000000-0000-4000-8000-000000000513'
+    const secondMessageId =
+      '00000000-0000-4000-8000-000000000514'
+    const rolledBackMessageId =
+      '00000000-0000-4000-8000-000000000515'
+    database.replaceConversations([
+      {
+        id: firstConversationId,
+        title: '第一对话',
+        updatedAt: 1,
+        messages: [
+          {
+            id: firstMessageId,
+            role: 'user',
+            content: '第一条',
+            createdAt: 1,
+            state: 'complete'
+          }
+        ]
+      },
+      {
+        id: secondConversationId,
+        title: '第二对话',
+        updatedAt: 2,
+        messages: [
+          {
+            id: secondMessageId,
+            role: 'assistant',
+            content: '第二条',
+            createdAt: 2,
+            state: 'complete'
+          }
+        ]
+      }
+    ])
+
+    expect(() =>
+      database.saveLocalConversations([
+        {
+          header: {
+            id: firstConversationId,
+            title: '不应提交的标题',
+            updatedAt: 3
+          },
+          messages: [
+            {
+              id: rolledBackMessageId,
+              role: 'user',
+              content: '不应提交',
+              createdAt: 3,
+              state: 'complete'
+            },
+            {
+              id: secondMessageId,
+              role: 'assistant',
+              content: '错误归属',
+              createdAt: 2,
+              state: 'complete'
+            }
+          ]
+        }
+      ])
+    ).toThrow('消息 ID 已属于其他对话')
+    expect(database.getConversation(firstConversationId)).toMatchObject({
+      title: '第一对话',
+      messages: [{ id: firstMessageId }]
+    })
+
+    expect(() =>
+      database.saveLocalConversations([
+        {
+          header: {
+            id: firstConversationId,
+            title: '仍不应提交的标题',
+            updatedAt: 4
+          },
+          messages: [
+            {
+              id: firstMessageId,
+              role: 'assistant',
+              content: '错误角色',
+              createdAt: 1,
+              state: 'complete'
+            }
+          ]
+        }
+      ])
+    ).toThrow('消息角色不能更改')
+    expect(database.getConversation(firstConversationId)).toMatchObject({
+      title: '第一对话',
+      messages: [
+        {
+          id: firstMessageId,
+          role: 'user',
+          content: '第一条'
+        }
+      ]
+    })
+    database.close()
+  })
+
+  it('explicitly deletes only local conversations and cascades messages', async () => {
+    const database = await createDatabase()
+    const localId = '00000000-0000-4000-8000-000000000521'
+    database.replaceConversations([
+      {
+        id: localId,
+        title: '待删除本地对话',
+        updatedAt: 1,
+        messages: [
+          {
+            id: '00000000-0000-4000-8000-000000000522',
+            role: 'user',
+            content: '待删除消息',
+            createdAt: 1,
+            state: 'complete'
+          }
+        ]
+      }
+    ])
+    const channelProject = database.ensureChannelProjects(
+      'C:\\Users\\test',
+      channelDefaultProfileId
+    )[0]!
+    const remote = database.getOrCreateRemoteConversation({
+      projectId: channelProject.id,
+      channel: 'weixin',
+      accountId: 'default',
+      externalConversationId: 'protected-delete',
+      conversationType: 'direct',
+      title: '受保护远程对话',
+      accountDisplay: '发送者 ****0521'
+    })
+    database.appendRemoteConversationMessage({
+      conversationId: remote.id,
+      role: 'user',
+      content: '远程消息'
+    })
+
+    expect(database.deleteLocalConversation(localId)).toBe(true)
+    expect(database.deleteLocalConversation(localId)).toBe(false)
+    expect(() =>
+      database.getConversation(localId)
+    ).toThrow('对话不存在')
+    expect(() =>
+      database.deleteLocalConversation(remote.id)
+    ).toThrow('远程对话不能作为本地对话删除')
+    expect(() =>
+      database.saveLocalConversations([
+        {
+          header: {
+            id: remote.id,
+            title: '冲突本地标题',
+            updatedAt: 2
+          },
+          messages: []
+        }
+      ])
+    ).toThrow('本地对话 ID 与远程对话冲突')
+    expect(database.getConversation(remote.id)).toMatchObject({
+      title: '受保护远程对话',
+      messages: [{ content: '远程消息' }]
+    })
+    database.close()
+  })
+
+  it('gets a targeted conversation outside the latest 100', async () => {
+    const database = await createDatabase()
+    database.saveLocalConversations(
+      Array.from({ length: 100 }, (_, index) => ({
+        header: {
+          id: `00000000-0000-4000-8000-${String(index + 1).padStart(12, '0')}`,
+          title: `较新对话 ${index}`,
+          updatedAt: index + 2
+        },
+        messages: []
+      }))
+    )
+    const oldestId = '00000000-0000-4000-8000-000000000999'
+    database.saveLocalConversations([
+      {
+        header: {
+          id: oldestId,
+          title: '第 101 个对话',
+          updatedAt: 1
+        },
+        messages: []
+      }
+    ])
+
+    expect(database.listConversations()).toHaveLength(100)
+    expect(
+      database.listConversations().some(
+        (conversation) => conversation.id === oldestId
+      )
+    ).toBe(false)
+    expect(database.getConversation(oldestId)).toMatchObject({
+      id: oldestId,
+      title: '第 101 个对话',
+      messages: []
+    })
+    database.close()
+  })
+
   it('repairs unattended channel selections without rebinding ordinary conversations', async () => {
     const database = await createDatabase()
     const removedProfileId =

src/main/assistant/assistant-database.ts

@@ -14,6 +14,7 @@ import type {
   AssistantProject,
   AssistantSchedule,
   AssistantTask,
+  ConversationMessage,
   ConversationSnapshot,
   ExpertCreateInput,
   ExpertUpdateInput,
@@ -21,6 +22,7 @@ import type {
   HeartbeatSummaryOutput,
   HeartbeatUpdateInput,
   LegacyWorkMode,
+  LocalConversationSaveBatch,
   MemoryCreateInput,
   ModelUsageCallInput,
   ProjectChannel,
@@ -749,6 +751,80 @@ function interruptActiveToolBlocks(
   )
 }
 
+function toConversationSnapshot(
+  conversation: ConversationRow,
+  messages: MessageRow[]
+): ConversationSnapshot {
+  return {
+    id: conversation.id,
+    projectId: conversation.project_id ?? undefined,
+    runtimeSelection: parseRuntimeSelection(
+      conversation.runtime_selection_json
+    ),
+    knowledgeRetrievalMode:
+      conversation.knowledge_retrieval_mode ?? undefined,
+    ...(conversation.channel &&
+    conversation.conversation_type &&
+    conversation.account_display
+      ? {
+          remote: {
+            channel: conversation.channel,
+            accountDisplay: conversation.account_display,
+            conversationType: conversation.conversation_type
+          }
+        }
+      : {}),
+    title: conversation.title,
+    updatedAt: Date.parse(conversation.updated_at),
+    messages: messages.map((message) => {
+      const metadata = JSON.parse(
+        message.metadata_json
+      ) as MessageMetadata
+      const interrupted = message.state === 'streaming'
+      return {
+        id: message.id,
+        role: message.role,
+        content: message.content,
+        reasoning: metadata.reasoning,
+        blocks: interrupted
+          ? interruptActiveToolBlocks(metadata.blocks)
+          : metadata.blocks,
+        createdAt:
+          metadata.createdAt ?? Date.parse(message.created_at),
+        state: interrupted ? ('error' as const) : message.state,
+        status: interrupted
+          ? interruptedMessageStatus
+          : metadata.status,
+        tools: interrupted
+          ? interruptActiveTools(metadata.tools)
+          : metadata.tools,
+        sources: metadata.sources,
+        sourceReferences: metadata.sourceReferences,
+        knowledgeRetrieval: metadata.knowledgeRetrieval,
+        artifactIds: metadata.artifactIds,
+        attachments: metadata.attachments
+      }
+    })
+  }
+}
+
+function serializeConversationMessageMetadata(
+  message: ConversationMessage
+): string {
+  return JSON.stringify({
+    createdAt: message.createdAt,
+    status: message.status,
+    reasoning: message.reasoning,
+    blocks: message.blocks,
+    tools: message.tools,
+    sources: message.sources,
+    sourceReferences: message.sourceReferences,
+    knowledgeRetrieval: message.knowledgeRetrieval,
+    artifactIds: message.artifactIds,
+    attachments: message.attachments
+  })
+}
+
 export class AssistantDatabase {
   private database?: DatabaseSync
   private channelEventWrites = 0
@@ -1279,69 +1355,45 @@ export class AssistantDatabase {
        )
        ORDER BY sequence ASC`
     )
-    return conversations.map((conversation) => ({
-      id: conversation.id,
-      projectId: conversation.project_id ?? undefined,
-      runtimeSelection: parseRuntimeSelection(
-        conversation.runtime_selection_json
-      ),
-      knowledgeRetrievalMode:
-        conversation.knowledge_retrieval_mode ?? undefined,
-      ...(conversation.channel &&
-      conversation.conversation_type &&
-      conversation.account_display
-        ? {
-            remote: {
-              channel: conversation.channel,
-              accountDisplay: conversation.account_display,
-              conversationType: conversation.conversation_type
-            }
-          }
-        : {}),
-      title: conversation.title,
-      updatedAt: Date.parse(conversation.updated_at),
-      messages: (
+    return conversations.map((conversation) =>
+      toConversationSnapshot(
+        conversation,
         messageStatement.all(conversation.id) as MessageRow[]
-      ).map((message) => {
-        const metadata = JSON.parse(
-          message.metadata_json
-        ) as MessageMetadata
-        const interrupted = message.state === 'streaming'
-        return {
-          id: message.id,
-          role: message.role,
-          content: message.content,
-          reasoning: metadata.reasoning,
-          blocks: interrupted
-            ? interruptActiveToolBlocks(metadata.blocks)
-            : metadata.blocks,
-          createdAt:
-            metadata.createdAt ?? Date.parse(message.created_at),
-          state: interrupted ? ('error' as const) : message.state,
-          status: interrupted
-            ? interruptedMessageStatus
-            : metadata.status,
-          tools: interrupted
-            ? interruptActiveTools(metadata.tools)
-            : metadata.tools,
-          sources: metadata.sources,
-          sourceReferences: metadata.sourceReferences,
-          knowledgeRetrieval: metadata.knowledgeRetrieval,
-          artifactIds: metadata.artifactIds,
-          attachments: metadata.attachments
-        }
-      })
-    }))
+      )
+    )
   }
 
   getConversation(conversationId: string): ConversationSnapshot {
-    const conversation = this.listConversations().find(
-      (candidate) => candidate.id === conversationId
+    const database = this.requireDatabase()
+    const conversation = database
+      .prepare(
+        `SELECT id, project_id, runtime_selection_json,
+                knowledge_retrieval_mode, title, channel,
+                external_account_id, external_conversation_id,
+                conversation_type, account_display, updated_at
+         FROM conversations
+         WHERE id = ? AND status = 'active'`
       )
+      .get(conversationId) as ConversationRow | undefined
     if (!conversation) {
       throw new Error('对话不存在')
     }
-    return conversation
+    const messages = database
+      .prepare(
+        `SELECT id, conversation_id, role, content, state, metadata_json,
+                created_at
+         FROM (
+           SELECT id, conversation_id, role, content, state,
+                  metadata_json, created_at, sequence
+           FROM messages
+           WHERE conversation_id = ?
+           ORDER BY sequence DESC
+           LIMIT 500
+         )
+         ORDER BY sequence ASC`
+      )
+      .all(conversationId) as MessageRow[]
+    return toConversationSnapshot(conversation, messages)
   }
 
   repairConversationRuntimeSelections(
@@ -1502,6 +1554,167 @@ export class AssistantDatabase {
     }
   }
 
+  saveLocalConversations(batch: LocalConversationSaveBatch): void {
+    const database = this.requireDatabase()
+    const findConversation = database.prepare(
+      'SELECT channel FROM conversations WHERE id = ?'
+    )
+    const insertConversation = database.prepare(
+      `INSERT INTO conversations
+        (id, project_id, runtime_selection_json, knowledge_retrieval_mode,
+         work_mode, title, status, created_at, updated_at)
+       VALUES (?, ?, ?, ?, 'ask', ?, 'active', ?, ?)`
+    )
+    const updateConversation = database.prepare(
+      `UPDATE conversations
+       SET project_id = ?, runtime_selection_json = ?,
+           knowledge_retrieval_mode = ?, title = ?, status = 'active',
+           updated_at = ?
+       WHERE id = ? AND channel IS NULL`
+    )
+    const findMessage = database.prepare(
+      `SELECT conversation_id, role
+       FROM messages
+       WHERE id = ?`
+    )
+    const nextSequence = database.prepare(
+      `SELECT COALESCE(MAX(sequence), -1) + 1 AS sequence
+       FROM messages
+       WHERE conversation_id = ?`
+    )
+    const insertMessage = database.prepare(
+      `INSERT INTO messages
+        (id, conversation_id, request_id, role, content, state, sequence,
+         metadata_json, created_at)
+       VALUES (?, ?, NULL, ?, ?, ?, ?, ?, ?)`
+    )
+    const updateMessage = database.prepare(
+      `UPDATE messages
+       SET content = ?, state = ?, metadata_json = ?
+       WHERE id = ?`
+    )
+    const trimMessages = database.prepare(
+      `DELETE FROM messages
+       WHERE id IN (
+         SELECT id
+         FROM messages
+         WHERE conversation_id = ?
+         ORDER BY sequence DESC
+         LIMIT -1 OFFSET 500
+       )`
+    )
+
+    database.exec('BEGIN IMMEDIATE')
+    try {
+      for (const save of batch) {
+        const { header } = save
+        const existingConversation = findConversation.get(
+          header.id
+        ) as { channel: ProjectChannel | null } | undefined
+        const updatedAt = new Date(header.updatedAt).toISOString()
+        if (existingConversation?.channel) {
+          throw new Error('本地对话 ID 与远程对话冲突')
+        }
+        if (existingConversation) {
+          const result = updateConversation.run(
+            header.projectId ?? null,
+            header.runtimeSelection
+              ? JSON.stringify(header.runtimeSelection)
+              : null,
+            header.knowledgeRetrievalMode ?? null,
+            header.title,
+            updatedAt,
+            header.id
+          )
+          if (result.changes !== 1) {
+            throw new Error('无法更新本地对话')
+          }
+        } else {
+          insertConversation.run(
+            header.id,
+            header.projectId ?? null,
+            header.runtimeSelection
+              ? JSON.stringify(header.runtimeSelection)
+              : null,
+            header.knowledgeRetrievalMode ?? null,
+            header.title,
+            updatedAt,
+            updatedAt
+          )
+        }
+
+        let sequence = (
+          nextSequence.get(header.id) as { sequence: number }
+        ).sequence
+        let insertedMessage = false
+        for (const message of save.messages) {
+          const existingMessage = findMessage.get(message.id) as
+            | {
+                conversation_id: string
+                role: MessageRow['role']
+              }
+            | undefined
+          if (existingMessage) {
+            if (existingMessage.conversation_id !== header.id) {
+              throw new Error('消息 ID 已属于其他对话')
+            }
+            if (existingMessage.role !== message.role) {
+              throw new Error('消息角色不能更改')
+            }
+            updateMessage.run(
+              message.content,
+              message.state,
+              serializeConversationMessageMetadata(message),
+              message.id
+            )
+            continue
+          }
+          insertMessage.run(
+            message.id,
+            header.id,
+            message.role,
+            message.content,
+            message.state,
+            sequence,
+            serializeConversationMessageMetadata(message),
+            new Date(message.createdAt).toISOString()
+          )
+          sequence += 1
+          insertedMessage = true
+        }
+        if (insertedMessage) {
+          trimMessages.run(header.id)
+        }
+      }
+      database.exec('COMMIT')
+    } catch (error) {
+      database.exec('ROLLBACK')
+      throw error
+    }
+  }
+
+  deleteLocalConversation(conversationId: string): boolean {
+    const database = this.requireDatabase()
+    const conversation = database
+      .prepare('SELECT channel FROM conversations WHERE id = ?')
+      .get(conversationId) as
+      | { channel: ProjectChannel | null }
+      | undefined
+    if (!conversation) {
+      return false
+    }
+    if (conversation.channel) {
+      throw new Error('远程对话不能作为本地对话删除')
+    }
+    return (
+      database
+        .prepare(
+          'DELETE FROM conversations WHERE id = ? AND channel IS NULL'
+        )
+        .run(conversationId).changes === 1
+    )
+  }
+
   getOrCreateRemoteConversation(input: {
     projectId: string
     channel: ProjectChannel

src/main/ipc.test.ts

@@ -4,7 +4,7 @@ import { tmpdir } from 'node:os'
 import { join } from 'node:path'
 import { ipcChannels } from '../shared/ipc-channels'
 import type { AssistantProject } from '../shared/assistant-contracts'
-import type { BrowserLiveState } from '../shared/contracts'
+import type { AgentEvent, BrowserLiveState } from '../shared/contracts'
 import { defaultKnowledgeOntologySettings } from '../shared/knowledge-ontology'
 import { AssistantDatabase } from './assistant/assistant-database'
 import { registerIpcHandlers } from './ipc'
@@ -1715,6 +1715,177 @@ describe('registerIpcHandlers token usage', () => {
   })
 })
 
+describe('registerIpcHandlers local conversation persistence', () => {
+  afterEach(() => {
+    electronMocks.handlers.clear()
+    vi.clearAllMocks()
+  })
+
+  it('validates and forwards incremental saves and explicit deletions', async () => {
+    const assistantDatabase = {
+      claimDueSchedules: vi.fn(() => []),
+      saveLocalConversations: vi.fn(),
+      deleteLocalConversation: vi.fn(() => true)
+    }
+    const webContents = {
+      mainFrame: {
+        url: 'file:///goodbuddy/index.html'
+      },
+      getURL: vi.fn(() => 'file:///goodbuddy/index.html')
+    }
+    const window = {
+      webContents,
+      isDestroyed: vi.fn(() => false),
+      on: vi.fn(),
+      removeListener: vi.fn()
+    }
+    const dispose = registerIpcHandlers(
+      window as never,
+      { capability: 'text' } as never,
+      'CommandOrControl+Shift+Space',
+      {} as never,
+      {} as never,
+      { clear: vi.fn() } as never,
+      {} as never,
+      assistantDatabase as never,
+      { clear: vi.fn() } as never,
+      {} as never,
+      vi.fn(async () => {})
+    )
+    const event = {
+      sender: webContents,
+      senderFrame: webContents.mainFrame
+    }
+    const conversationId =
+      '00000000-0000-4000-8000-000000000301'
+    const messageId = '00000000-0000-4000-8000-000000000302'
+    const batch = [
+      {
+        header: {
+          id: conversationId,
+          title: '增量会话',
+          updatedAt: 1
+        },
+        messages: [
+          {
+            id: messageId,
+            role: 'assistant' as const,
+            content: '增量内容',
+            createdAt: 1,
+            state: 'streaming' as const
+          }
+        ]
+      }
+    ]
+
+    expect(
+      electronMocks.handlers.get(
+        ipcChannels.conversationsSaveLocal
+      )?.(event, batch)
+    ).toBeUndefined()
+    expect(
+      assistantDatabase.saveLocalConversations
+    ).toHaveBeenCalledWith(batch)
+    expect(
+      electronMocks.handlers.get(
+        ipcChannels.conversationsDeleteLocal
+      )?.(event, conversationId)
+    ).toBe(true)
+    expect(
+      assistantDatabase.deleteLocalConversation
+    ).toHaveBeenCalledWith(conversationId)
+
+    expect(() =>
+      electronMocks.handlers.get(
+        ipcChannels.conversationsSaveLocal
+      )?.(event, [
+        {
+          ...batch[0],
+          header: {
+            ...batch[0]!.header,
+            remote: {
+              channel: 'weixin',
+              accountDisplay: 'remote',
+              conversationType: 'direct'
+            }
+          }
+        }
+      ])
+    ).toThrow()
+    expect(() =>
+      electronMocks.handlers.get(
+        ipcChannels.conversationsDeleteLocal
+      )?.(event, 'not-a-uuid')
+    ).toThrow()
+
+    await dispose()
+  })
+
+  it('waits for the renderer persistence acknowledgement before removing handlers', async () => {
+    const assistantDatabase = {
+      claimDueSchedules: vi.fn(() => [])
+    }
+    const webContents = {
+      mainFrame: {
+        url: 'file:///goodbuddy/index.html'
+      },
+      getURL: vi.fn(() => 'file:///goodbuddy/index.html'),
+      isDestroyed: vi.fn(() => false),
+      send: vi.fn()
+    }
+    const window = {
+      webContents,
+      isDestroyed: vi.fn(() => false),
+      on: vi.fn(),
+      removeListener: vi.fn()
+    }
+    const dispose = registerIpcHandlers(
+      window as never,
+      { capability: 'text' } as never,
+      'CommandOrControl+Shift+Space',
+      {} as never,
+      {} as never,
+      { clear: vi.fn() } as never,
+      {} as never,
+      assistantDatabase as never,
+      { clear: vi.fn() } as never,
+      {} as never,
+      vi.fn(async () => {})
+    )
+    const event = {
+      sender: webContents,
+      senderFrame: webContents.mainFrame
+    }
+    electronMocks.handlers.get(
+      ipcChannels.appRendererPersistenceReady
+    )?.(event)
+
+    const disposal = dispose()
+    await vi.waitFor(() =>
+      expect(webContents.send).toHaveBeenCalledWith(
+        ipcChannels.appRendererPersistenceRequest,
+        expect.any(String)
+      )
+    )
+    expect(
+      electronMocks.handlers.has(ipcChannels.conversationsSaveLocal)
+    ).toBe(true)
+    const requestId = webContents.send.mock.calls.find(
+      ([channel]) =>
+        channel === ipcChannels.appRendererPersistenceRequest
+    )?.[1]
+    expect(requestId).toEqual(expect.any(String))
+    electronMocks.handlers.get(
+      ipcChannels.appRendererPersistenceComplete
+    )?.(event, requestId)
+
+    await disposal
+    expect(
+      electronMocks.handlers.has(ipcChannels.conversationsSaveLocal)
+    ).toBe(false)
+  })
+})
+
 describe('registerIpcHandlers agent terminal state', () => {
   afterEach(() => {
     electronMocks.handlers.clear()
@@ -2258,6 +2429,105 @@ describe('registerIpcHandlers agent terminal state', () => {
     await harness.dispose()
   })
 
+  it('coalesces burst deltas while preserving output and terminal order', async () => {
+    const deltas = Array.from(
+      { length: 100 },
+      (_, index) => `chunk-${index};`
+    )
+    const expectedOutput = deltas.join('')
+    const runtime = {
+      runtimeId: 'model',
+      capability: 'chat',
+      supportsToolExecution: true,
+      async *run(request: { requestId: string }) {
+        for (const delta of deltas) {
+          yield {
+            requestId: request.requestId,
+            type: 'text',
+            delta
+          }
+        }
+        yield {
+          requestId: request.requestId,
+          type: 'tool',
+          callId: 'call-burst',
+          name: 'read',
+          state: 'completed',
+          summary: 'read completed'
+        }
+        yield { requestId: request.requestId, type: 'done' }
+      }
+    }
+    const harness = createHarness(runtime)
+    const requestId = '00000000-0000-4000-8000-000000000025'
+
+    await harness.handler?.(trustedEvent(harness.webContents), {
+      requestId,
+      conversationId: 'burst-stream',
+      prompt: 'stream',
+      workMode: 'ask',
+      knowledgeLibraryIds: []
+    })
+    await vi.waitFor(() =>
+      expect(harness.assistantDatabase.updateTaskStatus).toHaveBeenCalledWith(
+        requestId,
+        'completed'
+      )
+    )
+
+    const persistedEvents =
+      harness.assistantDatabase.appendTaskEvent.mock.calls
+        .filter(([taskId]) => taskId === requestId)
+        .map(([, , payload]) => payload)
+    const publicEvents = harness.webContents.send.mock.calls
+      .filter(([channel]) => channel === ipcChannels.agentEvent)
+      .map(([, payload]) => payload)
+      .filter((payload) => payload.requestId === requestId)
+    expect(persistedEvents).toHaveLength(3)
+    expect(publicEvents).toHaveLength(4)
+    expect(persistedEvents.map((event) => event.type)).toEqual([
+      'text',
+      'tool',
+      'done'
+    ])
+    expect(publicEvents.map((event) => event.type)).toEqual([
+      'text',
+      'text',
+      'tool',
+      'done'
+    ])
+    expect(publicEvents[0]).toEqual({
+      requestId,
+      type: 'text',
+      delta: deltas[0]
+    })
+    expect(persistedEvents[0]).toEqual({
+      requestId,
+      type: 'text',
+      delta: expectedOutput
+    })
+    expect(
+      publicEvents
+        .filter(
+          (
+            event
+          ): event is Extract<AgentEvent, { type: 'text' }> =>
+            event.type === 'text'
+        )
+        .map((event) => event.delta)
+        .join('')
+    ).toBe(expectedOutput)
+    expect(
+      harness.assistantDatabase.createTextArtifact
+    ).toHaveBeenCalledWith(
+      expect.objectContaining({
+        taskId: requestId,
+        content: expectedOutput
+      })
+    )
+    await harness.dispose()
+  })
+
   it('preflights always-retrieve mode and injects bounded untrusted evidence', async () => {
     const libraryId = '11111111-1111-4111-8111-111111111111'
     const documentId = '33333333-3333-4333-8333-333333333333'

src/main/ipc.ts

@@ -131,6 +131,7 @@ import {
 import {
   assistantIdSchema,
   conversationSnapshotsSchema,
+  localConversationSaveBatchSchema,
   memoryCreateSchema,
   normalizeInteractiveWorkMode,
   projectChannelLabels,
@@ -241,6 +242,7 @@ import {
   analyzeMagicNoteEntry,
   analyzeMagicTodo
 } from './magic-notes/magic-note-analyzer'
+import { AgentEventBuffer } from './agent-event-buffer'
 
 const requestIdSchema = z.string().uuid()
 const GOODBUDDY_RELEASES_URL =
@@ -832,6 +834,7 @@ export function registerIpcHandlers(
   goodbuddyConfigService?: GoodBuddyConfigService
 ): () => Promise<void> {
   const activeRequests = new Map<string, AbortController>()
+  const activeEventBuffers = new Map<string, { flush(): void }>()
   const pendingAgentQuestions = new Map<
     string,
     { requestId: string; runtime: AgentRuntime }
@@ -840,6 +843,8 @@ export function registerIpcHandlers(
   let shuttingDown = false
   let executionPaused = false
   let clearLocalDataOperation: Promise<void> | undefined
+  let rendererPersistenceReady = false
+  const pendingRendererPersistence = new Map<string, () => void>()
   let pendingGoodBuddyConfigReload = false
   let goodBuddyConfigReloadQueue: Promise<void> = Promise.resolve()
   const executionTracker = createPromiseTracker()
@@ -902,6 +907,40 @@ export function registerIpcHandlers(
     ipcMain.removeHandler(channel)
   }
 
+  const requestRendererPersistence = async (): Promise<void> => {
+    if (
+      !rendererPersistenceReady ||
+      window.isDestroyed() ||
+      (typeof window.webContents.isDestroyed === 'function' &&
+        window.webContents.isDestroyed())
+    ) {
+      return
+    }
+    const requestId = randomUUID()
+    const completion = new Promise<void>((resolve) => {
+      const finish = (): void => {
+        clearTimeout(timeout)
+        pendingRendererPersistence.delete(requestId)
+        resolve()
+      }
+      pendingRendererPersistence.set(requestId, finish)
+      const timeout = setTimeout(finish, 1_500)
+      timeout.unref?.()
+    })
+    window.webContents.send(
+      ipcChannels.appRendererPersistenceRequest,
+      requestId
+    )
+    await completion
+  }
+
+  const waitForRendererQuiescence = async (): Promise<void> => {
+    await Promise.allSettled([
+      executionTracker.drain(),
+      maintenanceTracker.drain()
+    ])
+  }
+
   const notifyMaximizedChanged = (): void => {
     if (!window.isDestroyed()) {
       window.webContents.send(
@@ -967,6 +1006,7 @@ export function registerIpcHandlers(
       },
       signal,
       (approvalEvent) => {
+        activeEventBuffers.get(event.requestId)?.flush()
         if (!window.isDestroyed()) {
           window.webContents.send(ipcChannels.agentEvent, approvalEvent)
         }
@@ -1029,6 +1069,7 @@ export function registerIpcHandlers(
     parentTaskId: string,
     event: Extract<AgentEvent, { type: 'subagent' }>
   ): void => {
+    activeEventBuffers.get(parentTaskId)?.flush()
     assistantDatabase.appendTaskEvent(
       parentTaskId,
       event.type,
@@ -1218,6 +1259,16 @@ export function registerIpcHandlers(
     let knowledgeCapabilityToken: string | undefined
     const resultAttachments: ChannelMediaAttachment[] = []
     const artifactIds: string[] = []
+    const eventBuffer = new AgentEventBuffer({
+      onError: (error) => controller.abort(error),
+      onEvent: (event) => {
+        assistantDatabase.appendTaskEvent(
+          requestId,
+          event.type,
+          event
+        )
+      }
+    })
     try {
       const requestRuntime =
         remoteContext?.runtime ??
@@ -1296,6 +1347,7 @@ export function registerIpcHandlers(
             },
             controller.signal,
             (approvalEvent) => {
+              eventBuffer.flush()
               if (!window.isDestroyed()) {
                 window.webContents.send(
                   ipcChannels.agentEvent,
@@ -1380,11 +1432,7 @@ export function registerIpcHandlers(
         if (taskEvent.type === 'artifact') {
           artifactIds.push(taskEvent.artifactId)
         }
-        assistantDatabase.appendTaskEvent(
-          requestId,
-          taskEvent.type,
-          taskEvent
-        )
+        eventBuffer.push(taskEvent)
         if (taskEvent.type === 'tool' && remoteContext) {
           publishRemoteActivity({
             requestId,
@@ -1474,6 +1522,7 @@ export function registerIpcHandlers(
         ...(artifactIds.length > 0 ? { artifactIds } : {})
       }
     } catch (error) {
+      eventBuffer.flush()
       const message = safeRuntimeError(error, '定时任务执行失败')
       assistantDatabase.updateTaskStatus(
         requestId,
@@ -1492,6 +1541,7 @@ export function registerIpcHandlers(
       })
       return { status: 'failed', error: message }
     } finally {
+      eventBuffer.close()
       externalSignal?.removeEventListener(
         'abort',
         abortFromExternal
@@ -2040,6 +2090,25 @@ export function registerIpcHandlers(
     }
   })
 
+  registerHandler(
+    ipcChannels.appRendererPersistenceReady,
+    (event) => {
+      assertTrustedSender(event, window)
+      rendererPersistenceReady = true
+    },
+    false
+  )
+
+  registerHandler(
+    ipcChannels.appRendererPersistenceComplete,
+    (event, input: unknown) => {
+      assertTrustedSender(event, window)
+      const requestId = requestIdSchema.parse(input)
+      pendingRendererPersistence.get(requestId)?.()
+    },
+    false
+  )
+
   registerHandler(ipcChannels.appShow, (event) => {
     assertTrustedSender(event, window)
     showWindow(window)
@@ -2280,10 +2349,58 @@ export function registerIpcHandlers(
     const execution = (async () => {
       let outputText = ''
       let completed = false
-      let persistedRuntimeError = false
+      let runtimeErrorEvent:
+        | Extract<AgentEvent, { type: 'error' }>
+        | undefined
       let executionRequest = request
       let preflightReferences: KnowledgeSearchReference[] = []
       let referencesPublished = false
+      const persistedEventBuffer = new AgentEventBuffer({
+        onError: (error) => controller.abort(error),
+        onEvent: (event) => {
+          assistantDatabase.appendTaskEvent(
+            request.requestId,
+            event.type,
+            event
+          )
+        }
+      })
+      const publicEventBuffer = new AgentEventBuffer({
+        flushIntervalMs: 16,
+        onError: (error) => controller.abort(error),
+        onEvent: (event) => {
+          if (!window.isDestroyed()) {
+            window.webContents.send(ipcChannels.agentEvent, event)
+          }
+        }
+      })
+      let publicStreamType: 'text' | 'reasoning' | undefined
+      const eventBuffer = {
+        push: (event: AgentEvent): void => {
+          const streamType =
+            event.type === 'text' || event.type === 'reasoning'
+              ? event.type
+              : undefined
+          const startsStreamSegment =
+            streamType !== undefined && streamType !== publicStreamType
+          publicStreamType = streamType
+          publicEventBuffer.push(event)
+          if (startsStreamSegment) {
+            publicEventBuffer.flush()
+          }
+          persistedEventBuffer.push(event)
+        },
+        flush: (): void => {
+          publicStreamType = undefined
+          publicEventBuffer.flush()
+          persistedEventBuffer.flush()
+        },
+        close: (): void => {
+          publicEventBuffer.close()
+          persistedEventBuffer.close()
+        }
+      }
+      activeEventBuffers.set(request.requestId, eventBuffer)
       const toolStates = new Map<
         string,
         Extract<AgentEvent, { type: 'tool' }>
@@ -2294,17 +2411,7 @@ export function registerIpcHandlers(
           { type: 'knowledge-retrieval' }
         >
       ): void => {
-        assistantDatabase.appendTaskEvent(
-          request.requestId,
-          retrievalEvent.type,
-          retrievalEvent
-        )
-        if (!window.isDestroyed()) {
-          window.webContents.send(
-            ipcChannels.agentEvent,
-            retrievalEvent
-          )
-        }
+        eventBuffer.push(retrievalEvent)
       }
       const publishReferences = (): void => {
         if (referencesPublished) {
@@ -2337,17 +2444,7 @@ export function registerIpcHandlers(
           type: 'source-references',
           references
         }
-        assistantDatabase.appendTaskEvent(
-          request.requestId,
-          referenceEvent.type,
-          referenceEvent
-        )
-        if (!window.isDestroyed()) {
-          window.webContents.send(
-            ipcChannels.agentEvent,
-            referenceEvent
-          )
-        }
+        eventBuffer.push(referenceEvent)
       }
       try {
         controller.signal.throwIfAborted()
@@ -2593,12 +2690,7 @@ export function registerIpcHandlers(
             })
           }
           if (publicEvent.type === 'error') {
-            assistantDatabase.appendTaskEvent(
-              request.requestId,
-              publicEvent.type,
-              publicEvent
-            )
-            persistedRuntimeError = true
+            runtimeErrorEvent = publicEvent
             throw new Error(publicEvent.message)
           }
           if (publicEvent.type === 'done') {
@@ -2615,12 +2707,15 @@ export function registerIpcHandlers(
               )
             }
             publishReferences()
-          }
+            eventBuffer.flush()
             assistantDatabase.appendTaskEvent(
               request.requestId,
               publicEvent.type,
               publicEvent
             )
+          } else {
+            eventBuffer.push(publicEvent)
+          }
           if (publicEvent.type === 'done') {
             completed = true
             if (outputText.trim()) {
@@ -2641,9 +2736,12 @@ export function registerIpcHandlers(
               title: 'GoodBuddy 任务已完成',
               body: '任务结果已保存到成果工作栏。'
             })
-          }
             if (!window.isDestroyed()) {
-            window.webContents.send(ipcChannels.agentEvent, publicEvent)
+              window.webContents.send(
+                ipcChannels.agentEvent,
+                publicEvent
+              )
+            }
           }
           if (completed) {
             break
@@ -2654,27 +2752,31 @@ export function registerIpcHandlers(
         }
       } catch (error) {
         publishReferences()
+        eventBuffer.flush()
         const errorMessage = controller.signal.aborted
           ? '请求已取消'
           : safeRuntimeError(error, 'Agent Runtime 执行失败')
+        const agentEvent: AgentEvent =
+          runtimeErrorEvent && !controller.signal.aborted
+            ? runtimeErrorEvent
+            : {
+                requestId: request.requestId,
+                type: 'error',
+                status: controller.signal.aborted
+                  ? 'cancelled'
+                  : 'failed',
+                message: errorMessage
+              }
         assistantDatabase.updateTaskStatus(
           request.requestId,
           controller.signal.aborted ? 'cancelled' : 'failed',
           errorMessage
         )
-        const agentEvent: AgentEvent = {
-          requestId: request.requestId,
-          type: 'error',
-          status: controller.signal.aborted ? 'cancelled' : 'failed',
-          message: errorMessage
-        }
-        if (!persistedRuntimeError) {
         assistantDatabase.appendTaskEvent(
           request.requestId,
           agentEvent.type,
           agentEvent
         )
-        }
         showDesktopNotificationWhenUnfocused(window, {
           title: controller.signal.aborted
             ? 'GoodBuddy 任务已取消'
@@ -2685,6 +2787,8 @@ export function registerIpcHandlers(
           window.webContents.send(ipcChannels.agentEvent, agentEvent)
         }
       } finally {
+        eventBuffer.close()
+        activeEventBuffers.delete(request.requestId)
         for (const [questionId, pending] of pendingAgentQuestions) {
           if (pending.requestId === request.requestId) {
             pendingAgentQuestions.delete(questionId)
@@ -3573,6 +3677,26 @@ export function registerIpcHandlers(
     }
   )
 
+  registerHandler(
+    ipcChannels.conversationsSaveLocal,
+    (event, input: unknown) => {
+      assertTrustedSender(event, window)
+      assistantDatabase.saveLocalConversations(
+        localConversationSaveBatchSchema.parse(input)
+      )
+    }
+  )
+
+  registerHandler(
+    ipcChannels.conversationsDeleteLocal,
+    (event, input: unknown) => {
+      assertTrustedSender(event, window)
+      return assistantDatabase.deleteLocalConversation(
+        assistantIdSchema.parse(input)
+      )
+    }
+  )
+
   registerHandler(
     ipcChannels.workspaceChangesGet,
     async (event, input: unknown) => {
@@ -5000,9 +5124,6 @@ export function registerIpcHandlers(
     clearInterval(scheduleInterval)
     window.removeListener('maximize', notifyMaximizedChanged)
     window.removeListener('unmaximize', notifyMaximizedChanged)
-    for (const channel of channels) {
-      ipcMain.removeHandler(channel)
-    }
     abortActiveRequests('应用正在退出')
     for (const controller of heartbeatControllers) {
       controller.abort(new Error('应用正在退出'))
@@ -5019,6 +5140,16 @@ export function registerIpcHandlers(
     approvalBroker.clear()
     goodbuddyConfigService?.clear()
     pendingGoodBuddyConfigReload = false
+    await waitForRendererQuiescence()
+    await requestRendererPersistence()
+    for (const channel of channels) {
+      ipcMain.removeHandler(channel)
+    }
+    rendererPersistenceReady = false
+    for (const complete of pendingRendererPersistence.values()) {
+      complete()
+    }
+    pendingRendererPersistence.clear()
     await goodBuddyConfigReloadQueue
     const channelCleanup = Promise.allSettled([
       ...channelServices.map((service) => service.stop()),

src/preload/index.ts

@@ -43,6 +43,7 @@ import type {
   AssistantTask,
   TokenUsageSummary,
   ConversationSnapshot,
+  LocalConversationSaveBatch,
   WorkspaceChanges,
   WorkspaceDirectoryListing,
   WorkspaceFilePreview,
@@ -146,6 +147,30 @@ const desktopApi: DesktopApi = {
           handler
         )
     },
+    onBeforeQuit: (listener) => {
+      const handler = (
+        _event: Electron.IpcRendererEvent,
+        requestId: string
+      ): void => {
+        const acknowledge = (): void => {
+          void ipcRenderer.invoke(
+            ipcChannels.appRendererPersistenceComplete,
+            requestId
+          )
+        }
+        void listener().then(acknowledge, acknowledge)
+      }
+      ipcRenderer.on(
+        ipcChannels.appRendererPersistenceRequest,
+        handler
+      )
+      void ipcRenderer.invoke(ipcChannels.appRendererPersistenceReady)
+      return () =>
+        ipcRenderer.removeListener(
+          ipcChannels.appRendererPersistenceRequest,
+          handler
+        )
+    },
     clearLocalData: async () => {
       await ipcRenderer.invoke(ipcChannels.appClearLocalData)
     },
@@ -555,6 +580,17 @@ const desktopApi: DesktopApi = {
         conversations
       )
     },
+    saveLocal: async (batch: LocalConversationSaveBatch) => {
+      await ipcRenderer.invoke(
+        ipcChannels.conversationsSaveLocal,
+        batch
+      )
+    },
+    deleteLocal: (conversationId: string) =>
+      ipcRenderer.invoke(
+        ipcChannels.conversationsDeleteLocal,
+        conversationId
+      ) as Promise<boolean>,
     onChanged: (listener) => {
       const handler = (): void => listener()
       ipcRenderer.on(ipcChannels.conversationsChanged, handler)

src/renderer/src/App.test.tsx

@@ -20,6 +20,26 @@ const speechRecognitionMocks = vi.hoisted(() => ({
   startPcmRecording: vi.fn()
 }))
 
+const lazyRouteMocks = vi.hoisted(() => {
+  let pending: Promise<void> | undefined
+  let releasePending: (() => void) | undefined
+  return {
+    suspendKnowledgeRoute(): void {
+      pending = new Promise((resolve) => {
+        releasePending = resolve
+      })
+    },
+    releaseKnowledgeRoute(): void {
+      releasePending?.()
+      releasePending = undefined
+      pending = undefined
+    },
+    async waitForKnowledgeRoute(): Promise<void> {
+      await pending
+    }
+  }
+})
+
 vi.mock('./speech-recognition', async (importOriginal) => ({
   ...(await importOriginal<
     typeof import('./speech-recognition')
@@ -27,6 +47,11 @@ vi.mock('./speech-recognition', async (importOriginal) => ({
   startPcmRecording: speechRecognitionMocks.startPcmRecording
 }))
 
+vi.mock('./KnowledgeWorkspace', async (importOriginal) => {
+  await lazyRouteMocks.waitForKnowledgeRoute()
+  return importOriginal<typeof import('./KnowledgeWorkspace')>()
+})
+
 import App from './App'
 import { loadActivityRecords } from './activity-store'
 import { changeUiLocale } from './i18n'
@@ -41,6 +66,7 @@ let fileSelectionProgressListener:
   | undefined
 let newConversationListener: (() => void) | undefined
 let maximizedChangedListener: ((maximized: boolean) => void) | undefined
+let beforeQuitListener: (() => Promise<void>) | undefined
 const removeMaximizedChangedListener = vi.fn()
 const run = vi.fn<DesktopApi['agent']['run']>()
 const modelProfileId = '00000000-0000-4000-8000-000000000001'
@@ -76,6 +102,12 @@ const api: DesktopApi = {
       maximizedChangedListener = listener
       return removeMaximizedChangedListener
     }),
+    onBeforeQuit: vi.fn((listener) => {
+      beforeQuitListener = listener
+      return () => {
+        beforeQuitListener = undefined
+      }
+    }),
     clearLocalData: vi.fn(async () => {}),
     onNewConversation: vi.fn((listener) => {
       newConversationListener = listener
@@ -289,6 +321,8 @@ const api: DesktopApi = {
   conversations: {
     list: vi.fn(async () => []),
     replace: vi.fn(async () => {}),
+    saveLocal: vi.fn(async () => {}),
+    deleteLocal: vi.fn(async () => true),
     onChanged: vi.fn(() => () => undefined)
   },
   workspace: {
@@ -664,7 +698,21 @@ describe('App', () => {
     delete document.documentElement.dataset.theme
     document.documentElement.style.colorScheme = ''
     vi.clearAllMocks()
+    vi.mocked(api.conversations.list).mockReset().mockResolvedValue([])
+    vi.mocked(api.conversations.replace)
+      .mockReset()
+      .mockResolvedValue()
+    vi.mocked(api.conversations.saveLocal)
+      .mockReset()
+      .mockResolvedValue()
+    vi.mocked(api.conversations.deleteLocal)
+      .mockReset()
+      .mockResolvedValue(true)
+    vi.mocked(api.conversations.onChanged)
+      .mockReset()
+      .mockReturnValue(() => undefined)
     newConversationListener = undefined
+    beforeQuitListener = undefined
     browserListener = undefined
     fileSelectionProgressListener = undefined
     maximizedChangedListener = undefined
@@ -774,6 +822,122 @@ describe('App', () => {
     expect(screen.getByText('GOODBUDDY 工作台')).toBeInTheDocument()
   })
 
+  it('shows an accessible fallback while a lazy route loads', async () => {
+    lazyRouteMocks.suspendKnowledgeRoute()
+    try {
+      render(<App />)
+
+      fireEvent.click(
+        await screen.findByRole('button', { name: '知识库' })
+      )
+
+      const loading = screen.getByRole('status', {
+        name: '正在加载页面…'
+      })
+      expect(loading).toHaveAttribute('aria-live', 'polite')
+      expect(loading).toHaveAttribute('aria-busy', 'true')
+      await act(async () => lazyRouteMocks.releaseKnowledgeRoute())
+      expect(
+        await screen.findByRole('heading', {
+          level: 1,
+          name: '知识库'
+        })
+      ).toBeInTheDocument()
+      expect(
+        screen.queryByRole('status', { name: '正在加载页面…' })
+      ).not.toBeInTheDocument()
+    } finally {
+      lazyRouteMocks.releaseKnowledgeRoute()
+    }
+  })
+
+  it('preserves title, message, and project filtering with deferred search', async () => {
+    vi.mocked(api.conversations.list).mockResolvedValueOnce([
+      {
+        id: '00000000-0000-4000-8000-000000000411',
+        projectId,
+        title: '标题里的 Alpha',
+        updatedAt: 1_775_000_000_003,
+        messages: [
+          {
+            id: '00000000-0000-4000-8000-000000000412',
+            role: 'assistant',
+            content: '普通正文',
+            createdAt: 1_775_000_000_003,
+            state: 'complete'
+          }
+        ]
+      },
+      {
+        id: '00000000-0000-4000-8000-000000000413',
+        projectId,
+        title: '正文命中的会话',
+        updatedAt: 1_775_000_000_002,
+        messages: [
+          {
+            id: '00000000-0000-4000-8000-000000000414',
+            role: 'user',
+            content: '这里包含 Beta Needle',
+            createdAt: 1_775_000_000_002,
+            state: 'complete'
+          }
+        ]
+      },
+      {
+        id: '00000000-0000-4000-8000-000000000415',
+        projectId: '00000000-0000-4000-8000-000000000999',
+        title: '其他项目里的 Alpha',
+        updatedAt: 1_775_000_000_001,
+        messages: [
+          {
+            id: '00000000-0000-4000-8000-000000000416',
+            role: 'user',
+            content: 'Beta Needle',
+            createdAt: 1_775_000_000_001,
+            state: 'complete'
+          }
+        ]
+      }
+    ])
+    const { container } = render(<App />)
+    const search = await screen.findByLabelText('搜索对话')
+    const conversationList =
+      container.querySelector<HTMLElement>('.conversation-list')
+    if (!conversationList) {
+      throw new Error('Missing conversation list')
+    }
+    expect(
+      await within(conversationList).findByText('标题里的 Alpha')
+    ).toBeInTheDocument()
+    expect(
+      within(conversationList).queryByText('其他项目里的 Alpha')
+    ).not.toBeInTheDocument()
+
+    fireEvent.change(search, { target: { value: 'beta needle' } })
+    expect(search).toHaveValue('beta needle')
+    await waitFor(() => {
+      expect(
+        within(conversationList).getByText('正文命中的会话')
+      ).toBeInTheDocument()
+      expect(
+        within(conversationList).queryByText('标题里的 Alpha')
+      ).not.toBeInTheDocument()
+    })
+
+    fireEvent.change(search, { target: { value: 'ALPHA' } })
+    await waitFor(() => {
+      expect(
+        within(conversationList).getByText('标题里的 Alpha')
+      ).toBeInTheDocument()
+      expect(
+        within(conversationList).queryByText('正文命中的会话')
+      ).not.toBeInTheDocument()
+      expect(
+        within(conversationList).queryByText('其他项目里的 Alpha')
+      ).not.toBeInTheDocument()
+    })
+  })
+
   it('keeps Settings open when the interface language changes', async () => {
     api.updates = {
       getSettings: vi.fn(async () => ({
@@ -1225,6 +1389,69 @@ describe('App', () => {
     ).not.toBeInTheDocument()
   })
 
+  it('renders the latest 80 messages and preserves scroll when revealing earlier messages', async () => {
+    vi.mocked(api.conversations.list).mockResolvedValueOnce([
+      {
+        id: '00000000-0000-4000-8000-000000000421',
+        projectId,
+        title: '超长会话',
+        updatedAt: 1_775_000_000_000,
+        messages: Array.from({ length: 161 }, (_, index) => ({
+          id: `00000000-0000-4000-8000-${String(index).padStart(12, '0')}`,
+          role: index % 2 === 0 ? ('user' as const) : ('assistant' as const),
+          content: `历史消息 ${String(index).padStart(3, '0')}`,
+          createdAt: 1_775_000_000_000 + index,
+          state: 'complete' as const
+        }))
+      }
+    ])
+    const { container } = render(<App />)
+
+    expect(await screen.findByText('历史消息 160')).toBeInTheDocument()
+    expect(screen.queryByText('历史消息 080')).not.toBeInTheDocument()
+    expect(container.querySelectorAll('.message')).toHaveLength(80)
+    const chat = container.querySelector<HTMLElement>('.chat')
+    if (!chat) {
+      throw new Error('Missing chat scroll container')
+    }
+    Object.defineProperties(chat, {
+      clientHeight: { configurable: true, value: 400 },
+      scrollHeight: {
+        configurable: true,
+        get: () => container.querySelectorAll('.message').length * 10
+      },
+      scrollTop: {
+        configurable: true,
+        writable: true,
+        value: 125
+      }
+    })
+
+    fireEvent.click(
+      screen.getByRole('button', {
+        name: '加载更早的消息（还剩 81 条）'
+      })
+    )
+
+    expect(container.querySelectorAll('.message')).toHaveLength(160)
+    expect(screen.getByText('历史消息 001')).toBeInTheDocument()
+    expect(screen.queryByText('历史消息 000')).not.toBeInTheDocument()
+    expect(chat.scrollTop).toBe(925)
+    fireEvent.click(
+      screen.getByRole('button', {
+        name: '加载更早的消息（还剩 1 条）'
+      })
+    )
+    expect(container.querySelectorAll('.message')).toHaveLength(161)
+    expect(screen.getByText('历史消息 000')).toBeInTheDocument()
+    expect(
+      screen.queryByRole('button', { name: /加载更早的消息/u })
+    ).not.toBeInTheDocument()
+    expect(
+      screen.getByText('历史消息 000').closest('article')
+    ).toHaveFocus()
+  })
+
   it('keeps the reader position while a response continues below', async () => {
     render(<App />)
     fireEvent.change(await screen.findByLabelText('向 GoodBuddy 提问'), {
@@ -1335,6 +1562,68 @@ describe('App', () => {
         })
       ).not.toBeInTheDocument()
     )
+    expect(api.conversations.deleteLocal).toHaveBeenCalledWith(
+      expect.any(String)
+    )
+  })
+
+  it('keeps a local conversation visible when deleting its persisted record fails', async () => {
+    const conversationId =
+      '00000000-0000-4000-8000-000000000431'
+    const title = '删除失败时保留的本地会话'
+    vi.mocked(api.conversations.list).mockResolvedValueOnce([
+      {
+        id: conversationId,
+        projectId,
+        title,
+        updatedAt: 1_775_000_000_000,
+        messages: [
+          {
+            id: '00000000-0000-4000-8000-000000000432',
+            role: 'assistant',
+            content: '需要保留的消息',
+            createdAt: 1_775_000_000_000,
+            state: 'complete'
+          }
+        ]
+      }
+    ])
+    vi.mocked(api.conversations.deleteLocal).mockRejectedValueOnce(
+      new Error('delete failed')
+    )
+    render(<App />)
+
+    fireEvent.click(
+      await screen.findByLabelText(`更多会话操作 ${title}`)
+    )
+    fireEvent.click(
+      screen.getByRole('button', { name: `删除对话 ${title}` })
+    )
+    fireEvent.click(
+      screen.getByRole('button', {
+        name: `确认永久删除对话 ${title}`
+      })
+    )
+
+    await waitFor(() =>
+      expect(api.conversations.deleteLocal).toHaveBeenCalledWith(
+        conversationId
+      )
+    )
+    expect(
+      await screen.findByText('删除本地会话失败，已保留当前对话')
+    ).toBeInTheDocument()
+    expect(screen.getByText('需要保留的消息')).toBeInTheDocument()
+    const dialog = screen.getByRole('alertdialog', {
+      name: `确认永久删除对话 ${title}`
+    })
+    expect(
+      dialog
+    ).toBeInTheDocument()
+    fireEvent.keyDown(dialog, { key: 'Escape' })
+    expect(
+      await screen.findByLabelText(`更多会话操作 ${title}`)
+    ).toBeInTheDocument()
   })
 
   it('keeps a conversation when cancelling its active task fails', async () => {
@@ -1576,6 +1865,155 @@ describe('App', () => {
     expect(screen.getByText('项目：默认项目')).toHaveClass('scope-badge')
   })
 
+  it('persists only the changed conversation and streamed assistant message', async () => {
+    const activeConversationId =
+      '00000000-0000-4000-8000-000000000441'
+    const activeMessageId =
+      '00000000-0000-4000-8000-000000000442'
+    const unrelatedConversationId =
+      '00000000-0000-4000-8000-000000000443'
+    const unrelatedMessageId =
+      '00000000-0000-4000-8000-000000000444'
+    vi.mocked(api.conversations.list).mockResolvedValueOnce([
+      {
+        id: activeConversationId,
+        projectId,
+        title: '增量持久化会话',
+        updatedAt: 1_775_000_000_002,
+        messages: [
+          {
+            id: activeMessageId,
+            role: 'assistant',
+            content: '原有消息',
+            createdAt: 1_775_000_000_002,
+            state: 'complete'
+          }
+        ]
+      },
+      {
+        id: unrelatedConversationId,
+        projectId,
+        title: '无关会话',
+        updatedAt: 1_775_000_000_001,
+        messages: [
+          {
+            id: unrelatedMessageId,
+            role: 'assistant',
+            content: '不应重复保存',
+            createdAt: 1_775_000_000_001,
+            state: 'complete'
+          }
+        ]
+      }
+    ])
+    render(<App />)
+    expect(await screen.findByText('原有消息')).toBeInTheDocument()
+
+    fireEvent.change(screen.getByLabelText('向 GoodBuddy 提问'), {
+      target: { value: '只更新当前会话' }
+    })
+    fireEvent.click(screen.getByLabelText('发送'))
+    await waitFor(() => expect(run).toHaveBeenCalledOnce())
+    const request = run.mock.calls[0]?.[0]
+    if (!request) {
+      throw new Error('Missing request')
+    }
+    await waitFor(() =>
+      expect(api.conversations.saveLocal).toHaveBeenCalled()
+    )
+    vi.mocked(api.conversations.saveLocal).mockClear()
+
+    act(() => {
+      agentListener?.({
+        requestId: request.requestId,
+        type: 'text',
+        delta: '流式增量'
+      })
+    })
+
+    await waitFor(
+      () => {
+        const batch = vi
+          .mocked(api.conversations.saveLocal)
+          .mock.calls.at(-1)?.[0]
+        expect(batch).toHaveLength(1)
+        expect(batch?.[0]?.header.id).toBe(activeConversationId)
+        expect(batch?.[0]?.messages).toEqual([
+          expect.objectContaining({
+            role: 'assistant',
+            content: '流式增量',
+            state: 'streaming'
+          })
+        ])
+        expect(
+          batch?.some(
+            (entry) => entry.header.id === unrelatedConversationId
+          )
+        ).toBe(false)
+        expect(
+          batch?.flatMap((entry) => entry.messages).some(
+            (message) =>
+              message.id === activeMessageId ||
+              message.id === unrelatedMessageId ||
+              message.role === 'user'
+          )
+        ).toBe(false)
+      },
+      { timeout: 2_000 }
+    )
+  })
+
+  it('flushes pending local conversation changes before quit', async () => {
+    const conversationId =
+      '00000000-0000-4000-8000-000000000445'
+    vi.mocked(api.conversations.list).mockResolvedValueOnce([
+      {
+        id: conversationId,
+        projectId,
+        title: '退出持久化会话',
+        updatedAt: 1_775_000_000_000,
+        messages: [
+          {
+            id: '00000000-0000-4000-8000-000000000446',
+            role: 'assistant',
+            content: '已有内容',
+            createdAt: 1_775_000_000_000,
+            state: 'complete'
+          }
+        ]
+      }
+    ])
+    render(<App />)
+    expect(await screen.findByText('已有内容')).toBeInTheDocument()
+    vi.mocked(api.conversations.saveLocal).mockClear()
+
+    fireEvent.change(screen.getByLabelText('向 GoodBuddy 提问'), {
+      target: { value: '退出前必须保存' }
+    })
+    fireEvent.click(screen.getByLabelText('发送'))
+    expect(
+      await screen.findByText('退出前必须保存')
+    ).toBeInTheDocument()
+    if (!beforeQuitListener) {
+      throw new Error('Missing before-quit persistence listener')
+    }
+
+    await act(async () => beforeQuitListener?.())
+
+    expect(api.conversations.saveLocal).toHaveBeenCalledWith([
+      expect.objectContaining({
+        header: expect.objectContaining({ id: conversationId }),
+        messages: expect.arrayContaining([
+          expect.objectContaining({
+            role: 'user',
+            content: '退出前必须保存',
+            state: 'complete'
+          })
+        ])
+      })
+    ])
+  })
+
   it('replaces the direct-model thinking status with real reasoning', async () => {
     render(<App />)
 
@@ -1773,9 +2211,9 @@ describe('App', () => {
     await waitFor(
       () => {
         const persistedMessages = vi
-          .mocked(api.conversations.replace)
-          .mock.calls.flatMap(([conversations]) =>
-            conversations.flatMap((conversation) => conversation.messages)
+          .mocked(api.conversations.saveLocal)
+          .mock.calls.flatMap(([batch]) =>
+            batch.flatMap((conversation) => conversation.messages)
           )
         const persisted = persistedMessages
           .filter((message) => message.role === 'assistant')
@@ -1864,12 +2302,12 @@ describe('App', () => {
     expect(screen.getByText('向量模型未配置')).toBeInTheDocument()
     await waitFor(() => {
       const snapshots = vi
-        .mocked(api.conversations.replace)
-        .mock.calls.at(-1)?.[0]
+        .mocked(api.conversations.saveLocal)
+        .mock.calls.flatMap(([batch]) => batch)
       expect(
         snapshots?.some(
           (conversation) =>
-            conversation.knowledgeRetrievalMode === 'always'
+            conversation.header.knowledgeRetrievalMode === 'always'
         )
       ).toBe(true)
     })
@@ -2007,7 +2445,7 @@ describe('App', () => {
     expect(anchorClick).toHaveBeenCalledOnce()
     await waitFor(
       () =>
-        expect(api.conversations.replace).toHaveBeenCalledWith(
+        expect(api.conversations.saveLocal).toHaveBeenCalledWith(
           expect.arrayContaining([
             expect.objectContaining({
               messages: expect.arrayContaining([
@@ -2844,14 +3282,14 @@ describe('App', () => {
           setTimeout(resolve, 550)
         })
     )
-    expect(api.conversations.replace).not.toHaveBeenCalledWith(
-      expect.arrayContaining([
-        expect.objectContaining({
-          projectId: channelProject.id,
-          remote: undefined
-        })
-      ])
+    const savedChannelHeaders = vi
+      .mocked(api.conversations.saveLocal)
+      .mock.calls.flatMap(([batch]) => batch.map((entry) => entry.header))
+    expect(
+      savedChannelHeaders.some(
+        (header) => header.projectId === channelProject.id
       )
+    ).toBe(false)
     expect(screen.getAllByText('尚无远程会话').length).toBeGreaterThan(0)
 
     fireEvent.click(screen.getByRole('button', { name: '打开设置' }))
@@ -3447,10 +3885,238 @@ describe('App', () => {
     )
   })
 
+  it('persists metadata-only retrieval and Runtime changes without rewriting messages', async () => {
+    const conversationId =
+      '00000000-0000-4000-8000-000000000451'
+    const existingMessageId =
+      '00000000-0000-4000-8000-000000000452'
+    const libraryId = '11111111-1111-4111-8111-111111111111'
+    const secondProfileId =
+      '00000000-0000-4000-8000-000000000453'
+    const settings = await api.settings.getRuntime()
+    vi.mocked(api.settings.getRuntime).mockResolvedValueOnce({
+      ...settings,
+      modelProfiles: [
+        ...settings.modelProfiles,
+        {
+          id: secondProfileId,
+          name: '仅元数据模型',
+          baseUrl: 'http://127.0.0.1:11434/v1',
+          modelName: 'qwen3',
+          protocol: 'openai-chat-completions',
+          authentication: 'none',
+          imageGenerationQuality: 'auto',
+          apiKeyConfigured: false,
+          credentialSource: 'none'
+        }
+      ]
+    })
+    vi.mocked(api.knowledge.getSnapshot).mockResolvedValueOnce({
+      libraries: [
+        {
+          id: libraryId,
+          name: '产品知识',
+          description: '',
+          storageMode: 'managed',
+          graphEnabled: false,
+          graphStrategy: 'rules',
+          sourceCount: 1,
+          documentCount: 1,
+          indexedDocumentCount: 1
+        }
+      ],
+      sources: [],
+      documents: [],
+      graphNodes: [],
+      graphRelations: [],
+      evidence: []
+    })
+    vi.mocked(api.conversations.list).mockResolvedValueOnce([
+      {
+        id: conversationId,
+        projectId,
+        runtimeSelection: {
+          provider: 'model',
+          profileId: modelProfileId
+        },
+        knowledgeRetrievalMode: 'auto',
+        title: '元数据会话',
+        updatedAt: 1_775_000_000_000,
+        messages: [
+          {
+            id: existingMessageId,
+            role: 'assistant',
+            content: '现有消息不应重写',
+            createdAt: 1_775_000_000_000,
+            state: 'complete'
+          }
+        ]
+      }
+    ])
+    vi.mocked(api.agent.getStatus).mockImplementation(
+      async (selection) => ({
+        id: 'model',
+        label:
+          selection?.provider === 'model' &&
+          selection.profileId === secondProfileId
+            ? 'qwen3'
+            : 'sonnet-5',
+        available: true,
+        supportsToolExecution: true,
+        detail: 'Ready'
+      })
+    )
+    render(<App />)
+
+    const knowledgeScope = await screen.findByRole('button', {
+      name: '选择知识库，本次已启用 1 个'
+    })
+    fireEvent.click(knowledgeScope)
+    fireEvent.click(
+      within(
+        screen.getByRole('group', { name: '知识检索方式' })
+      ).getByRole('button', { name: '每次先检索' })
+    )
+    await waitFor(
+      () =>
+        expect(api.conversations.saveLocal).toHaveBeenCalledWith([
+          {
+            header: expect.objectContaining({
+              id: conversationId,
+              knowledgeRetrievalMode: 'always'
+            }),
+            messages: []
+          }
+        ]),
+      { timeout: 2_000 }
+    )
+
+    vi.mocked(api.conversations.saveLocal).mockClear()
+    fireEvent.click(
+      screen.getByRole('button', { name: /sonnet-5/u })
+    )
+    fireEvent.click(
+      screen.getByRole('menuitemradio', {
+        name: /^仅元数据模型.*qwen3$/u
+      })
+    )
+    await waitFor(
+      () =>
+        expect(api.conversations.saveLocal).toHaveBeenCalledWith([
+          {
+            header: expect.objectContaining({
+              id: conversationId,
+              runtimeSelection: {
+                provider: 'model',
+                profileId: secondProfileId
+              },
+              knowledgeRetrievalMode: 'always'
+            }),
+            messages: []
+          }
+        ]),
+      { timeout: 2_000 }
+    )
+    const savedMessages = vi
+      .mocked(api.conversations.saveLocal)
+      .mock.calls.flatMap(([batch]) =>
+        batch.flatMap((entry) => entry.messages)
+      )
+    expect(
+      savedMessages.some((message) => message.id === existingMessageId)
+    ).toBe(false)
+  })
+
+  it('migrates legacy startup conversations with replace when SQLite has no local conversation', async () => {
+    const legacyConversation = {
+      id: '00000000-0000-4000-8000-000000000461',
+      title: '待迁移旧会话',
+      updatedAt: 1_775_000_000_000,
+      messages: [
+        {
+          id: '00000000-0000-4000-8000-000000000462',
+          role: 'assistant' as const,
+          content: '旧版浏览器存储消息',
+          createdAt: 1_775_000_000_000,
+          state: 'complete' as const
+        }
+      ]
+    }
+    localStorage.setItem(
+      'goodbuddy.conversations.v1',
+      JSON.stringify([legacyConversation])
+    )
+    render(<App />)
+
+    expect(
+      await screen.findByText('旧版浏览器存储消息')
+    ).toBeInTheDocument()
+    await waitFor(() =>
+      expect(api.conversations.replace).toHaveBeenCalledWith([
+        expect.objectContaining({
+          ...legacyConversation,
+          projectId
+        })
+      ])
+    )
+    expect(api.conversations.saveLocal).not.toHaveBeenCalled()
+  })
+
+  it('does not let remote rows displace legacy local conversations during migration', async () => {
+    const legacyConversations = [0, 1].map((index) => ({
+      id: `00000000-0000-4000-8000-${String(470 + index).padStart(12, '0')}`,
+      title: `待迁移本地会话 ${index}`,
+      updatedAt: 1_775_000_000_000 + index,
+      messages: [
+        {
+          id: `00000000-0000-4000-8001-${String(470 + index).padStart(12, '0')}`,
+          role: 'assistant' as const,
+          content: `待迁移消息 ${index}`,
+          createdAt: 1_775_000_000_000 + index,
+          state: 'complete' as const
+        }
+      ]
+    }))
+    localStorage.setItem(
+      'goodbuddy.conversations.v1',
+      JSON.stringify(legacyConversations)
+    )
+    const remoteProjectId =
+      '00000000-0000-4000-8000-000000000499'
+    vi.mocked(api.conversations.list).mockResolvedValueOnce(
+      Array.from({ length: 100 }, (_, index) => ({
+        id: `00000000-0000-4000-8002-${String(index).padStart(12, '0')}`,
+        projectId: remoteProjectId,
+        remote: {
+          channel: 'weixin' as const,
+          accountDisplay: `远程联系人 ${index}`,
+          conversationType: 'direct' as const
+        },
+        title: `远程会话 ${index}`,
+        updatedAt: 1_775_000_100_000 + index,
+        messages: []
+      }))
+    )
+    render(<App />)
+
+    await waitFor(() =>
+      expect(api.conversations.saveLocal).toHaveBeenCalled()
+    )
+    expect(api.conversations.replace).not.toHaveBeenCalled()
+    const migrated =
+      vi.mocked(api.conversations.saveLocal).mock.calls[0]?.[0] ?? []
+    expect(migrated.map((conversation) => conversation.header.id)).toEqual(
+      expect.arrayContaining(
+        legacyConversations.map((conversation) => conversation.id)
+      )
+    )
+  })
+
   it('preserves a legacy Auto conversation without silently persisting a replacement', async () => {
     vi.mocked(api.conversations.list).mockResolvedValueOnce([
       {
         id: '00000000-0000-4000-8000-000000000020',
+        projectId,
         runtimeSelection: { provider: 'auto' },
         title: '旧自动对话',
         updatedAt: 1,
@@ -3468,18 +4134,10 @@ describe('App', () => {
     render(<App />)
 
     expect(
-      await screen.findByRole('button', { name: /默认模型.*sonnet-5/u })
+      await screen.findByRole('button', { name: /自动.*sonnet-5/u })
     ).toBeInTheDocument()
-    await waitFor(() =>
-      expect(api.conversations.replace).toHaveBeenLastCalledWith(
-        expect.arrayContaining([
-          expect.objectContaining({
-            id: '00000000-0000-4000-8000-000000000020',
-            runtimeSelection: { provider: 'auto' }
-          })
-        ])
-      )
-    )
+    expect(api.conversations.replace).not.toHaveBeenCalled()
+    expect(api.conversations.saveLocal).not.toHaveBeenCalled()
   })
 
   it('keeps a removed model selection visible until the user replaces it', async () => {
@@ -3488,6 +4146,7 @@ describe('App', () => {
     vi.mocked(api.conversations.list).mockResolvedValueOnce([
       {
         id: '00000000-0000-4000-8000-000000000022',
+        projectId,
         runtimeSelection: {
           provider: 'model',
           profileId: removedProfileId
@@ -3507,19 +4166,14 @@ describe('App', () => {
     ])
     render(<App />)
 
-    await waitFor(() =>
-      expect(api.conversations.replace).toHaveBeenLastCalledWith(
-        expect.arrayContaining([
-          expect.objectContaining({
-            id: '00000000-0000-4000-8000-000000000022',
-            runtimeSelection: {
-              provider: 'model',
-              profileId: removedProfileId
-            }
-          })
-        ])
-      )
-    )
+    expect(
+      await screen.findByText('旧消息')
+    ).toBeInTheDocument()
+    expect(
+      screen.getByRole('button', { name: /模型配置不可用/u })
+    ).toBeInTheDocument()
+    expect(api.conversations.replace).not.toHaveBeenCalled()
+    expect(api.conversations.saveLocal).not.toHaveBeenCalled()
   })
 
   it('keeps model Runtime selection scoped to its conversation', async () => {
@@ -3614,14 +4268,17 @@ describe('App', () => {
 
     await waitFor(
       () =>
-        expect(api.conversations.replace).toHaveBeenLastCalledWith(
+        expect(api.conversations.saveLocal).toHaveBeenLastCalledWith(
           expect.arrayContaining([
             expect.objectContaining({
+              header: expect.objectContaining({
                 title: '第二模型对话',
                 runtimeSelection: {
                   provider: 'model',
                   profileId: secondProfileId
                 }
+              }),
+              messages: expect.any(Array)
             })
           ])
         ),
@@ -4855,7 +5512,9 @@ describe('App', () => {
       expect(
         screen.getByRole('button', { name: '新建笔记' })
       ).toBeInTheDocument()
+      await waitFor(() =>
         expect(api.magicNotes.list).toHaveBeenCalled()
+      )
       expect(
         screen.queryByLabelText('切换助手工作栏')
       ).not.toBeInTheDocument()

src/renderer/src/App.tsx

@@ -38,8 +38,13 @@ import {
   X
 } from 'lucide-react'
 import {
+  Component,
+  lazy,
+  Suspense,
   useCallback,
+  useDeferredValue,
   useEffect,
+  useLayoutEffect,
   useMemo,
   useReducer,
   useRef,
@@ -84,10 +89,13 @@ import type {
   AssistantExpert,
   AssistantTask,
   TokenUsageSummary,
+  ConversationMessage,
   ConversationSnapshot,
   ConversationAttachment,
   ConversationMessageBlock,
   ConversationToolActivity,
+  LocalConversationHeader,
+  LocalConversationSaveBatch,
   ProjectCreateInput,
   InteractiveWorkMode,
   ProjectChannel,
@@ -109,13 +117,10 @@ import {
   upsertActivityRecord,
   type ActivityRecord
 } from './activity-store'
-import { KnowledgeWorkspace } from './KnowledgeWorkspace'
 import {
   KnowledgeCitationDialog,
   type KnowledgeCitationContextView
 } from './KnowledgeCitationDialog'
-import { HeartbeatCenter } from './HeartbeatCenter'
-import { MagicNotesWorkspace } from './MagicNotesWorkspace'
 import { MarkdownRenderer } from './MarkdownRenderer'
 import {
   DestructiveConfirmActions,
@@ -133,7 +138,6 @@ import {
   type PendingSidebarApproval,
   type SidebarArtifact
 } from './RightAssistantSidebar'
-import { SettingsPanel } from './SettingsPanel'
 import type { SettingsCategoryId } from './settings-categories'
 import goodbuddyDarkIcon from './assets/goodbuddy-dark.png'
 import goodbuddyLightIcon from './assets/goodbuddy-light.png'
@@ -158,6 +162,30 @@ import type {
 import type { ReleaseNotesSnapshot } from '../../shared/release-notes-contracts'
 import { ReleaseNotesDialog } from './ReleaseNotesDialog'
 
+const KnowledgeWorkspace = lazy(async () => {
+  const module = await import('./KnowledgeWorkspace')
+  return { default: module.KnowledgeWorkspace }
+})
+
+const HeartbeatCenter = lazy(async () => {
+  const module = await import('./HeartbeatCenter')
+  return { default: module.HeartbeatCenter }
+})
+
+const MagicNotesWorkspace = lazy(async () => {
+  const module = await import('./MagicNotesWorkspace')
+  return { default: module.MagicNotesWorkspace }
+})
+
+const SettingsPanel = lazy(async () => {
+  const module = await import('./SettingsPanel')
+  return { default: module.SettingsPanel }
+})
+
+const messageRenderBatchSize = 80
+const conversationPersistenceIntervalMs = 500
+const conversationSearchSnapshotDelayMs = 250
+
 type AppNotification = {
   id: string
   message: string
@@ -206,6 +234,58 @@ function appNotificationReducer(
   return [...errors, ...transient]
 }
 
+function RouteLoadingStatus({
+  label
+}: {
+  label: string
+}): React.JSX.Element {
+  return (
+    <div
+      aria-busy="true"
+      aria-label={label}
+      aria-live="polite"
+      className="route-loading-status"
+      role="status"
+    >
+      <LoaderCircle aria-hidden="true" size={20} />
+      <span>{label}</span>
+    </div>
+  )
+}
+
+class RouteErrorBoundary extends Component<
+  { children: ReactNode; fallback: ReactNode },
+  { failed: boolean }
+> {
+  state = { failed: false }
+
+  static getDerivedStateFromError(): { failed: boolean } {
+    return { failed: true }
+  }
+
+  render(): ReactNode {
+    return this.state.failed ? this.props.fallback : this.props.children
+  }
+}
+
+function RouteLoadError({
+  message,
+  reloadLabel
+}: {
+  message: string
+  reloadLabel: string
+}): React.JSX.Element {
+  return (
+    <div className="route-load-error" role="alert">
+      <CircleAlert aria-hidden="true" size={20} />
+      <strong>{message}</strong>
+      <button onClick={() => window.location.reload()} type="button">
+        {reloadLabel}
+      </button>
+    </div>
+  )
+}
+
 function AppNotificationItem({
   notification,
   dispatch
@@ -735,6 +815,14 @@ function loadConversations(
   }
 }
 
+function hasConversationMigrationStorage(): boolean {
+  try {
+    return localStorage.getItem(storageKey) !== null
+  } catch {
+    return false
+  }
+}
+
 function loadActiveProjectId(): string | undefined {
   try {
     return localStorage.getItem(activeProjectStorageKey) || undefined
@@ -803,15 +891,24 @@ function isConversation(value: unknown): value is Conversation {
 function toConversationSnapshots(
   conversations: Conversation[]
 ): ConversationSnapshot[] {
-  return conversations.slice(0, 100).map((conversation) => ({
+  return conversations
+    .filter((conversation) => !conversation.remote)
+    .slice(0, 100)
+    .map((conversation) => ({
       id: conversation.id,
       projectId: conversation.projectId,
       runtimeSelection: conversation.runtimeSelection,
       knowledgeRetrievalMode: conversation.knowledgeRetrievalMode,
-    remote: conversation.remote,
       title: conversation.title,
       updatedAt: conversation.updatedAt,
-    messages: conversation.messages.slice(-500).map((message) => ({
+      messages: conversation.messages
+        .slice(-500)
+        .map(toConversationMessage)
+    }))
+}
+
+function toConversationMessage(message: Message): ConversationMessage {
+  return {
     id: message.id,
     role: message.role,
     content: message.content,
@@ -826,8 +923,59 @@ function toConversationSnapshots(
     knowledgeRetrieval: message.knowledgeRetrieval,
     artifactIds: message.artifactIds,
     attachments: message.attachments
-    }))
-  }))
+  }
+}
+
+function toLocalConversationHeader(
+  conversation: Conversation
+): LocalConversationHeader {
+  return {
+    id: conversation.id,
+    projectId: conversation.projectId,
+    runtimeSelection: conversation.runtimeSelection,
+    knowledgeRetrievalMode: conversation.knowledgeRetrievalMode,
+    title: conversation.title,
+    updatedAt: conversation.updatedAt
+  }
+}
+
+function createLocalConversationSaveBatch(
+  conversations: readonly Conversation[],
+  persisted: ReadonlyMap<string, Conversation>,
+  deletingConversationIds: ReadonlySet<string>
+): {
+  batch: LocalConversationSaveBatch
+  acknowledgements: Conversation[]
+} {
+  const batch: LocalConversationSaveBatch = []
+  const acknowledgements: Conversation[] = []
+  for (const conversation of conversations) {
+    if (
+      conversation.remote ||
+      deletingConversationIds.has(conversation.id) ||
+      persisted.get(conversation.id) === conversation
+    ) {
+      continue
+    }
+    const previous = persisted.get(conversation.id)
+    const previousMessages = new Map(
+      previous?.messages.map((message) => [message.id, message]) ?? []
+    )
+    batch.push({
+      header: toLocalConversationHeader(conversation),
+      messages: conversation.messages
+        .filter(
+          (message) => previousMessages.get(message.id) !== message
+        )
+        .slice(-500)
+        .map(toConversationMessage)
+    })
+    acknowledgements.push(conversation)
+    if (batch.length === 100) {
+      break
+    }
+  }
+  return { batch, acknowledgements }
 }
 
 function mergeArtifacts(
@@ -1307,6 +1455,9 @@ function App(): React.JSX.Element {
     tRef.current = t
   }, [t])
   const locale = i18n.resolvedLanguage === 'en-US' ? 'en-US' : 'zh-CN'
+  const conversationMigrationStoragePresent = useRef(
+    hasConversationMigrationStorage()
+  )
   const [conversations, setConversations] = useState(() =>
     loadConversations(
       t('conversation.greeting'),
@@ -1316,6 +1467,14 @@ function App(): React.JSX.Element {
   const [activeId, setActiveId] = useState(() => conversations[0]?.id ?? '')
   const activeConversationIdRef = useRef(activeId)
   const conversationsRef = useRef(conversations)
+  const persistedLocalConversationsRef = useRef(
+    new Map<string, Conversation>()
+  )
+  const conversationPersistenceQueueRef =
+    useRef<Promise<void>>(Promise.resolve())
+  const conversationPersistencePausedRef = useRef(false)
+  const deletingLocalConversationIdsRef = useRef(new Set<string>())
+  const flushConversationPersistenceAfterRenderRef = useRef(false)
   const [unreadConversationIds, setUnreadConversationIds] = useState<
     Set<string>
   >(() => new Set())
@@ -1509,6 +1668,9 @@ function App(): React.JSX.Element {
     useState<ProjectChannel>()
   const [magicNotesEnabled, setMagicNotesEnabled] = useState(false)
   const [searchQuery, setSearchQuery] = useState('')
+  const deferredSearchQuery = useDeferredValue(searchQuery)
+  const [searchConversationSnapshot, setSearchConversationSnapshot] =
+    useState(conversations)
   const [conversationActionsId, setConversationActionsId] = useState('')
   const [confirmingConversationId, setConfirmingConversationId] =
     useState('')
@@ -1591,6 +1753,7 @@ function App(): React.JSX.Element {
   const [activityRecords, setActivityRecords] = useState<ActivityRecord[]>(
     loadActivityRecords
   )
+  const activityRecordsRef = useRef(activityRecords)
   const activeRuns = useRef(new Map<string, ActiveRun>())
   const preparingConversations = useRef(new Set<string>())
   const hydratingArtifactIds = useRef(new Set<string>())
@@ -1599,6 +1762,17 @@ function App(): React.JSX.Element {
   const scrollRef = useRef<HTMLElement>(null)
   const chatPinnedToBottomRef = useRef(true)
   const chatScrollContextRef = useRef(`${view}:${activeId}`)
+  const prependScrollPositionRef = useRef<{
+    conversationId: string
+    scrollHeight: number
+    scrollTop: number
+  } | undefined>(undefined)
+  const finalRevealedMessageIdRef = useRef<string | undefined>(undefined)
+  const messageArticleRefs = useRef(new Map<string, HTMLElement>())
+  const [visibleMessageWindow, setVisibleMessageWindow] = useState(() => ({
+    conversationId: activeId,
+    count: messageRenderBatchSize
+  }))
   const [showScrollToBottom, setShowScrollToBottom] = useState(false)
   const sidebarRef = useRef<HTMLElement>(null)
   const sidebarToggleRef = useRef<HTMLButtonElement>(null)
@@ -1678,10 +1852,21 @@ function App(): React.JSX.Element {
     }
   }, [closeNarrowSidebar, narrowWindow, sidebarOpen])
 
-  useEffect(() => {
+  useLayoutEffect(() => {
     conversationsRef.current = conversations
   }, [conversations])
 
+  useEffect(() => {
+    if (!searchQuery.trim()) {
+      return
+    }
+    const timeout = window.setTimeout(
+      () => setSearchConversationSnapshot(conversations),
+      conversationSearchSnapshotDelayMs
+    )
+    return () => window.clearTimeout(timeout)
+  }, [conversations, searchQuery])
+
   useEffect(() => {
     projectsRef.current = projects
   }, [projects])
@@ -1801,6 +1986,70 @@ function App(): React.JSX.Element {
     () => conversations.find((conversation) => conversation.id === activeId),
     [activeId, conversations]
   )
+  const visibleMessageCount =
+    visibleMessageWindow.conversationId === activeId
+      ? visibleMessageWindow.count
+      : messageRenderBatchSize
+  const visibleMessageStartIndex = Math.max(
+    0,
+    (activeConversation?.messages.length ?? 0) - visibleMessageCount
+  )
+  const visibleMessages =
+    activeConversation?.messages.slice(visibleMessageStartIndex) ?? []
+  const hiddenMessageCount = visibleMessageStartIndex
+
+  const revealEarlierMessages = useCallback((): void => {
+    const scrollContainer = scrollRef.current
+    if (scrollContainer) {
+      prependScrollPositionRef.current = {
+        conversationId: activeId,
+        scrollHeight: scrollContainer.scrollHeight,
+        scrollTop: scrollContainer.scrollTop
+      }
+    }
+    const currentCount =
+      visibleMessageWindow.conversationId === activeId
+        ? visibleMessageWindow.count
+        : messageRenderBatchSize
+    if (
+      activeConversation &&
+      currentCount + messageRenderBatchSize >=
+        activeConversation.messages.length
+    ) {
+      finalRevealedMessageIdRef.current =
+        activeConversation.messages[0]?.id
+    }
+    setVisibleMessageWindow({
+      conversationId: activeId,
+      count: currentCount + messageRenderBatchSize
+    })
+  }, [activeConversation, activeId, visibleMessageWindow])
+
+  useLayoutEffect(() => {
+    const previous = prependScrollPositionRef.current
+    if (!previous) {
+      return
+    }
+    prependScrollPositionRef.current = undefined
+    if (previous.conversationId !== activeId) {
+      return
+    }
+    const scrollContainer = scrollRef.current
+    if (!scrollContainer) {
+      return
+    }
+    scrollContainer.scrollTop =
+      previous.scrollTop +
+      (scrollContainer.scrollHeight - previous.scrollHeight)
+    const finalRevealedMessageId = finalRevealedMessageIdRef.current
+    finalRevealedMessageIdRef.current = undefined
+    if (finalRevealedMessageId) {
+      messageArticleRefs.current
+        .get(finalRevealedMessageId)
+        ?.focus({ preventScroll: true })
+    }
+  }, [activeId, visibleMessageWindow])
+
   const activeRuntimeSelection = useMemo(
     () =>
       activeConversation?.runtimeSelection ??
@@ -2050,8 +2299,11 @@ function App(): React.JSX.Element {
     [activeProjectId, projects]
   )
   const filteredConversations = useMemo(() => {
-    const query = searchQuery.trim().toLocaleLowerCase()
-    return conversations.filter(
+    const query = deferredSearchQuery.trim().toLocaleLowerCase()
+    const candidates = query
+      ? searchConversationSnapshot
+      : conversations
+    return candidates.filter(
       (conversation) =>
         (!activeProjectId ||
           conversation.projectId === activeProjectId) &&
@@ -2063,7 +2315,13 @@ function App(): React.JSX.Element {
           message.content.toLocaleLowerCase().includes(query)
         ))
     )
-  }, [activeProject, activeProjectId, conversations, searchQuery])
+  }, [
+    activeProject,
+    activeProjectId,
+    conversations,
+    deferredSearchQuery,
+    searchConversationSnapshot
+  ])
   const pendingSidebarApprovals = useMemo<PendingSidebarApproval[]>(
     () =>
       conversations.flatMap((conversation) =>
@@ -2866,6 +3124,7 @@ function App(): React.JSX.Element {
           }
         })
         activeRuns.current.delete(event.requestId)
+        flushConversationPersistenceAfterRenderRef.current = true
       }
     },
     [
@@ -2892,14 +3151,33 @@ function App(): React.JSX.Element {
     viewRef.current = view
   }, [view])
 
-  useEffect(() => {
-    if (!conversationStoreReady) {
+  const persistLocalConversationChanges = useCallback((): void => {
+    const operation = conversationPersistenceQueueRef.current.then(
+      async () => {
+        if (conversationPersistencePausedRef.current) {
           return
         }
-    const timeout = setTimeout(() => {
-      void window.goodbuddy.conversations
-        .replace(toConversationSnapshots(conversations))
-        .catch(() => {
+        const { batch, acknowledgements } =
+          createLocalConversationSaveBatch(
+            conversationsRef.current,
+            persistedLocalConversationsRef.current,
+            deletingLocalConversationIdsRef.current
+          )
+        if (batch.length === 0) {
+          return
+        }
+        await window.goodbuddy.conversations.saveLocal(batch)
+        for (const conversation of acknowledgements) {
+          persistedLocalConversationsRef.current.set(
+            conversation.id,
+            conversation
+          )
+        }
+      }
+    )
+    conversationPersistenceQueueRef.current =
+      operation.catch(() => undefined)
+    void operation.catch(() => {
       notify({
         tone: 'error',
         message: tRef.current(
@@ -2908,9 +3186,51 @@ function App(): React.JSX.Element {
         dedupeKey: 'conversation-persistence'
       })
     })
-    }, 500)
-    return () => clearTimeout(timeout)
-  }, [conversationStoreReady, conversations])
+  }, [])
+
+  useEffect(() => {
+    if (!conversationStoreReady) {
+      return
+    }
+    persistLocalConversationChanges()
+    const interval = window.setInterval(
+      persistLocalConversationChanges,
+      conversationPersistenceIntervalMs
+    )
+    return () => {
+      window.clearInterval(interval)
+      persistLocalConversationChanges()
+    }
+  }, [conversationStoreReady, persistLocalConversationChanges])
+
+  useEffect(() => {
+    if (
+      !conversationStoreReady ||
+      !flushConversationPersistenceAfterRenderRef.current
+    ) {
+      return
+    }
+    flushConversationPersistenceAfterRenderRef.current = false
+    persistLocalConversationChanges()
+  }, [
+    conversationStoreReady,
+    conversations,
+    persistLocalConversationChanges
+  ])
+
+  useEffect(
+    () =>
+      window.goodbuddy.app.onBeforeQuit(async () => {
+        saveActivityRecords(activityRecordsRef.current)
+        if (!conversationStoreReady) {
+          return
+        }
+        flushConversationPersistenceAfterRenderRef.current = false
+        persistLocalConversationChanges()
+        await conversationPersistenceQueueRef.current
+      }),
+    [conversationStoreReady, persistLocalConversationChanges]
+  )
 
   useEffect(() => {
     if (!conversationStoreReady) {
@@ -2993,9 +3313,20 @@ function App(): React.JSX.Element {
   }, [conversationStoreReady])
 
   useEffect(() => {
+    activityRecordsRef.current = activityRecords
+    const timeout = window.setTimeout(() => {
       saveActivityRecords(activityRecords)
+    }, 250)
+    return () => window.clearTimeout(timeout)
   }, [activityRecords])
 
+  useEffect(
+    () => () => {
+      saveActivityRecords(activityRecordsRef.current)
+    },
+    []
+  )
+
   useEffect(() => {
     let active = true
     void Promise.all([
@@ -3016,14 +3347,34 @@ function App(): React.JSX.Element {
         setWorkMode(
           normalizeInteractiveWorkMode(project.defaultWorkMode)
         )
-        let nextConversations: Conversation[] =
-          persistedConversations.length > 0
-            ? persistedConversations
-            : migrationConversations.current.map((conversation) =>
+        const persistedLocalConversations =
+          persistedConversations.filter(
+            (conversation) => !conversation.remote
+          )
+        const persistedConversationIds = new Set(
+          persistedConversations.map((conversation) => conversation.id)
+        )
+        const shouldMigrateLocalStorage =
+          conversationMigrationStoragePresent.current ||
+          persistedConversations.length === 0
+        const migratedLocalConversations =
+          shouldMigrateLocalStorage
+            ? migrationConversations.current
+                .filter(
+                  (conversation) =>
+                    !conversation.remote &&
+                    !persistedConversationIds.has(conversation.id)
+                )
+                .map((conversation) =>
                   conversation.projectId || project.kind === 'channel'
                     ? conversation
                     : { ...conversation, projectId: project.id }
                 )
+            : []
+        let nextConversations: Conversation[] = [
+          ...persistedConversations,
+          ...migratedLocalConversations
+        ]
         let projectConversation = nextConversations.find(
           (conversation) =>
             conversation.projectId === project.id &&
@@ -3041,17 +3392,71 @@ function App(): React.JSX.Element {
             ...nextConversations
           ]
         }
-        if (persistedConversations.length === 0) {
-          await window.goodbuddy.conversations.replace(
-            toConversationSnapshots(nextConversations)
+        const acknowledgedLocalConversations = new Map(
+          persistedLocalConversations.map((conversation) => [
+            conversation.id,
+            conversation
+          ])
         )
+        if (
+          nextConversations.some(
+            (conversation) =>
+              !conversation.remote &&
+              acknowledgedLocalConversations.get(conversation.id) !==
+                conversation
+          )
+        ) {
+          if (persistedConversations.length === 0) {
+            const migratedSnapshots =
+              toConversationSnapshots(nextConversations)
+            await window.goodbuddy.conversations.replace(
+              migratedSnapshots
+            )
+            const migratedSnapshotIds = new Set(
+              migratedSnapshots.map((conversation) => conversation.id)
+            )
+            for (const conversation of nextConversations) {
+              if (migratedSnapshotIds.has(conversation.id)) {
+                acknowledgedLocalConversations.set(
+                  conversation.id,
+                  conversation
+                )
+              }
+            }
+          }
+          while (true) {
+            const migration = createLocalConversationSaveBatch(
+              nextConversations,
+              acknowledgedLocalConversations,
+              new Set()
+            )
+            if (migration.batch.length === 0) {
+              break
+            }
+            await window.goodbuddy.conversations.saveLocal(
+              migration.batch
+            )
+            for (const conversation of migration.acknowledgements) {
+              acknowledgedLocalConversations.set(
+                conversation.id,
+                conversation
+              )
+            }
+          }
         }
         if (!active) {
           return
         }
+        persistedLocalConversationsRef.current =
+          acknowledgedLocalConversations
         setConversations(nextConversations)
         setActiveId(projectConversation?.id ?? '')
+        try {
           localStorage.removeItem(storageKey)
+          conversationMigrationStoragePresent.current = false
+        } catch {
+          // The SQLite migration has already completed successfully.
+        }
         setConversationStoreReady(true)
       })
       .catch((reason: unknown) => {
@@ -3857,6 +4262,27 @@ function App(): React.JSX.Element {
       setDeletingConversationId('')
       return
     }
+    const deletingConversation = conversations.find(
+      (conversation) => conversation.id === conversationId
+    )
+    if (deletingConversation && !deletingConversation.remote) {
+      deletingLocalConversationIdsRef.current.add(conversationId)
+      try {
+        await conversationPersistenceQueueRef.current
+        await window.goodbuddy.conversations.deleteLocal(conversationId)
+        persistedLocalConversationsRef.current.delete(conversationId)
+      } catch {
+        deletingLocalConversationIdsRef.current.delete(conversationId)
+        notify({
+          tone: 'error',
+          message: t(
+            'notices.deleteConversationPersistenceFailed'
+          )
+        })
+        setDeletingConversationId('')
+        return
+      }
+    }
     setConfirmingConversationId('')
     setDeletingConversationId('')
     if (conversationActionsId === conversationId) {
@@ -3882,6 +4308,8 @@ function App(): React.JSX.Element {
     const remaining = conversations.filter(
       (conversation) => conversation.id !== conversationId
     )
+    conversationsRef.current = remaining
+    deletingLocalConversationIdsRef.current.delete(conversationId)
     const projectRemaining = remaining.filter(
       (conversation) => conversation.projectId === activeProjectId
     )
@@ -4726,6 +5154,9 @@ function App(): React.JSX.Element {
   }
 
   const clearLocalData = async (): Promise<void> => {
+    conversationPersistencePausedRef.current = true
+    try {
+      await conversationPersistenceQueueRef.current
       for (const requestId of activeRuns.current.keys()) {
         await window.goodbuddy.agent.cancel(requestId)
       }
@@ -4747,6 +5178,8 @@ function App(): React.JSX.Element {
           : undefined,
         t('conversation.greeting')
       )
+      conversationsRef.current = [conversation]
+      persistedLocalConversationsRef.current.clear()
       setConversations([conversation])
       setActiveId(conversation.id)
       setActivityRecords([])
@@ -4774,6 +5207,10 @@ function App(): React.JSX.Element {
         tone: 'success',
         message: t('notices.localDataCleared')
       })
+    } finally {
+      conversationPersistencePausedRef.current = false
+      persistLocalConversationChanges()
+    }
   }
 
   const isRunning =
@@ -5161,7 +5598,7 @@ function App(): React.JSX.Element {
           {filteredConversations.length === 0 && (
             <p className="conversation-empty">
               {activeProject?.kind === 'channel' &&
-              !searchQuery.trim()
+              !deferredSearchQuery.trim()
                 ? t('conversation.noRemote')
                 : t('conversation.noMatches')}
             </p>
@@ -5382,10 +5819,33 @@ function App(): React.JSX.Element {
           )}
 
           <div className="message-list">
-            {activeConversation?.messages.map((message, messageIndex) => (
+            {hiddenMessageCount > 0 && (
+              <button
+                className="load-earlier-messages"
+                onClick={revealEarlierMessages}
+                type="button"
+              >
+                {t('chat.loadEarlierMessages', {
+                  count: hiddenMessageCount
+                })}
+              </button>
+            )}
+            {activeConversation &&
+              visibleMessages.map((message, visibleMessageIndex) => {
+                const messageIndex =
+                  visibleMessageStartIndex + visibleMessageIndex
+                return (
                   <article
                 className={`message message--${message.role}`}
                 key={message.id}
+                ref={(element) => {
+                  if (element) {
+                    messageArticleRefs.current.set(message.id, element)
+                  } else {
+                    messageArticleRefs.current.delete(message.id)
+                  }
+                }}
+                tabIndex={-1}
               >
                 <div className="message__avatar">
                   {message.role === 'assistant' ? (
@@ -5932,7 +6392,8 @@ function App(): React.JSX.Element {
                     )}
                 </div>
                   </article>
-            ))}
+                )
+              })}
           </div>
             </section>
             {showScrollToBottom && (
@@ -6624,10 +7085,40 @@ function App(): React.JSX.Element {
           </PageShell>
         ) : view === 'magic-notes' && magicNotesEnabled ? (
           <PageShell variant="master-detail">
+            <RouteErrorBoundary
+              key="magic-notes"
+              fallback={
+                <RouteLoadError
+                  message={t('route.loadFailed')}
+                  reloadLabel={t('route.reload')}
+                />
+              }
+            >
+              <Suspense
+                fallback={
+                  <RouteLoadingStatus label={t('route.loading')} />
+                }
+              >
                 <MagicNotesWorkspace onNotify={notify} />
+              </Suspense>
+            </RouteErrorBoundary>
           </PageShell>
         ) : view === 'knowledge' ? (
           <PageShell variant="master-detail">
+            <RouteErrorBoundary
+              key="knowledge"
+              fallback={
+                <RouteLoadError
+                  message={t('route.loadFailed')}
+                  reloadLabel={t('route.reload')}
+                />
+              }
+            >
+              <Suspense
+                fallback={
+                  <RouteLoadingStatus label={t('route.loading')} />
+                }
+              >
                 <KnowledgeWorkspace
               documents={knowledgeSnapshot.documents}
               evidence={knowledgeSnapshot.evidence}
@@ -6909,9 +7400,25 @@ function App(): React.JSX.Element {
               sources={knowledgeSnapshot.sources}
               tasks={knowledgeSnapshot.tasks}
                 />
+              </Suspense>
+            </RouteErrorBoundary>
           </PageShell>
         ) : view === 'heartbeat' ? (
           <PageShell variant="dashboard">
+            <RouteErrorBoundary
+              key="heartbeat"
+              fallback={
+                <RouteLoadError
+                  message={t('route.loadFailed')}
+                  reloadLabel={t('route.reload')}
+                />
+              }
+            >
+              <Suspense
+                fallback={
+                  <RouteLoadingStatus label={t('route.loading')} />
+                }
+              >
                 <HeartbeatCenter
               configs={assistantHeartbeats}
               currentProjectName={activeProject?.name}
@@ -6931,8 +7438,24 @@ function App(): React.JSX.Element {
               runs={heartbeatRuns}
               tasks={assistantTasks}
                 />
+              </Suspense>
+            </RouteErrorBoundary>
           </PageShell>
         ) : view === 'settings' ? (
+          <RouteErrorBoundary
+            key="settings"
+            fallback={
+              <RouteLoadError
+                message={t('route.loadFailed')}
+                reloadLabel={t('route.reload')}
+              />
+            }
+          >
+            <Suspense
+              fallback={
+                <RouteLoadingStatus label={t('route.loading')} />
+              }
+            >
               <SettingsPanel
             appearanceTheme={appearanceTheme}
             heartbeats={assistantHeartbeats}
@@ -6973,6 +7496,8 @@ function App(): React.JSX.Element {
             open
             presentation="page"
               />
+            </Suspense>
+          </RouteErrorBoundary>
         ) : (
           <PageShell variant="dashboard">
             <ActivityPanel

src/renderer/src/activity-store.test.ts

@@ -105,6 +105,24 @@ describe('activity-store', () => {
     )
   })
 
+  it('drops the oldest records until the stored JSON fits the load bound', () => {
+    const records = Array.from(
+      { length: MAX_ACTIVITY_RECORDS },
+      (_, index) => ({
+        ...makeRecord(index),
+        detail: 'x'.repeat(4_000)
+      })
+    )
+
+    expect(saveActivityRecords(records)).toBe(true)
+    const serialized = localStorage.getItem(ACTIVITY_STORAGE_KEY)
+    expect(serialized?.length).toBeLessThanOrEqual(2_000_000)
+    const restored = loadActivityRecords()
+    expect(restored.length).toBeGreaterThan(0)
+    expect(restored.length).toBeLessThan(MAX_ACTIVITY_RECORDS)
+    expect(restored[0]?.id).toBe('activity-0')
+  })
+
   it('reports rejected writes without throwing', () => {
     const rejectingStorage = {
       setItem: () => {

src/renderer/src/activity-store.ts

@@ -278,8 +278,9 @@ export function loadActivityRecords(
 }
 
 /**
- * Persists at most 500 schema-valid records. Returns false if storage is
- * unavailable or rejects the write.
+ * Persists as many of the newest schema-valid records as fit within the
+ * bounded storage payload. Returns false if storage is unavailable or rejects
+ * the write.
  */
 export function saveActivityRecords(
   records: readonly ActivityRecord[],
@@ -289,19 +290,32 @@ export function saveActivityRecords(
     return false
   }
 
-  const safeRecords: ActivityRecord[] = []
+  const serializedRecords: string[] = []
+  let serializedLength = 2
   for (const record of records) {
     const safeRecord = parseActivityRecord(record)
     if (safeRecord) {
-      safeRecords.push(safeRecord)
+      const serializedRecord = JSON.stringify(safeRecord)
+      const nextLength =
+        serializedLength +
+        serializedRecord.length +
+        (serializedRecords.length > 0 ? 1 : 0)
+      if (nextLength > MAX_STORED_JSON_LENGTH) {
+        break
       }
-    if (safeRecords.length === MAX_ACTIVITY_RECORDS) {
+      serializedRecords.push(serializedRecord)
+      serializedLength = nextLength
+    }
+    if (serializedRecords.length === MAX_ACTIVITY_RECORDS) {
       break
     }
   }
 
   try {
-    storage.setItem(ACTIVITY_STORAGE_KEY, JSON.stringify(safeRecords))
+    storage.setItem(
+      ACTIVITY_STORAGE_KEY,
+      `[${serializedRecords.join(',')}]`
+    )
     return true
   } catch {
     return false

src/renderer/src/i18n/locales/en-US/app.ts

@@ -49,6 +49,11 @@ export const app = {
     activity: 'Tasks & Activity',
     pendingSuggestions: '{{count}} pending suggestions'
   },
+  route: {
+    loading: 'Loading page…',
+    loadFailed: 'The page component failed to load. Reload the app.',
+    reload: 'Reload'
+  },
   sidebar: {
     label: 'Main sidebar',
     newConversation: 'New conversation',
@@ -226,6 +231,7 @@ export const app = {
       }
     },
     retry: 'Edit and send again',
+    loadEarlierMessages: 'Load earlier messages ({{count}} remaining)',
     scrollToBottom: 'Scroll to bottom',
     status: {
       responseTruncated: 'The response was too long and was truncated locally',
@@ -419,6 +425,8 @@ export const app = {
       'Channel conversations are created automatically when the client receives a new message',
     deleteConversationCancelFailed:
       'Could not stop the running task, so the conversation was not deleted',
+    deleteConversationPersistenceFailed:
+      'Could not delete the local conversation, so it was kept',
     deletedConversationBrowserCloseFailed:
       'Failed to close the browser for the deleted conversation',
     conversationCopied: 'Conversation copied to the clipboard',

src/renderer/src/i18n/locales/zh-CN/app.ts

@@ -45,6 +45,11 @@ export const app = {
     activity: '任务与活动',
     pendingSuggestions: '{{count}} 条待处理建议'
   },
+  route: {
+    loading: '正在加载页面…',
+    loadFailed: '页面组件加载失败，请重新加载应用',
+    reload: '重新加载'
+  },
   sidebar: {
     label: '主侧栏',
     newConversation: '新建对话',
@@ -219,6 +224,7 @@ export const app = {
       }
     },
     retry: '重新编辑并发送',
+    loadEarlierMessages: '加载更早的消息（还剩 {{count}} 条）',
     scrollToBottom: '到底部',
     status: {
       responseTruncated: '回答过长，已在本地截断显示',
@@ -395,6 +401,8 @@ export const app = {
       '通道项目的会话由客户端收到新消息后自动创建',
     deleteConversationCancelFailed:
       '停止会话中的运行任务失败，尚未删除对话',
+    deleteConversationPersistenceFailed:
+      '删除本地会话失败，已保留当前对话',
     deletedConversationBrowserCloseFailed: '关闭已删除对话的浏览器失败',
     conversationCopied: '对话已复制到剪贴板',
     clipboardUnavailable: '无法访问剪贴板，请检查系统权限',

src/renderer/src/styles.css

@@ -3126,7 +3126,30 @@ button > svg {
   gap: 4px;
 }
 
+.load-earlier-messages {
+  align-self: center;
+  min-height: var(--control-height);
+  padding: var(--space-1) var(--space-3);
+  border: 1px solid var(--border-default);
+  border-radius: var(--radius-control);
+  background: var(--surface-raised);
+  color: var(--text-secondary);
+  cursor: pointer;
+}
+
+.load-earlier-messages:hover {
+  border-color: var(--accent-selected);
+  color: var(--text-primary);
+}
+
+.load-earlier-messages:focus-visible {
+  outline: 2px solid var(--accent);
+  outline-offset: 2px;
+}
+
 .message {
+  content-visibility: auto;
+  contain-intrinsic-block-size: auto 160px;
   display: grid;
   min-width: 0;
   padding: 17px 8px;
@@ -3138,6 +3161,56 @@ button > svg {
   grid-template-columns: minmax(0, 1fr) 30px;
 }
 
+.route-loading-status {
+  display: flex;
+  min-height: min(360px, 50vh);
+  align-items: center;
+  justify-content: center;
+  gap: var(--space-2);
+  color: var(--text-secondary);
+}
+
+.route-loading-status > svg {
+  animation: route-loading-spin 1s linear infinite;
+}
+
+.route-load-error {
+  display: flex;
+  min-height: min(360px, 50vh);
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  padding: var(--space-5);
+  gap: var(--space-3);
+  color: var(--text-secondary);
+  text-align: center;
+}
+
+.route-load-error > svg {
+  color: var(--danger-solid);
+}
+
+.route-load-error > button {
+  min-height: var(--control-height);
+  padding: var(--space-1) var(--space-3);
+  border: 1px solid var(--border-default);
+  border-radius: var(--radius-control);
+  background: var(--surface-raised);
+  color: var(--text-primary);
+  cursor: pointer;
+}
+
+.route-load-error > button:focus-visible {
+  outline: 2px solid var(--accent);
+  outline-offset: 2px;
+}
+
+@keyframes route-loading-spin {
+  to {
+    transform: rotate(360deg);
+  }
+}
+
 .message__avatar {
   display: grid;
   width: 29px;

src/shared/assistant-contracts.ts

@@ -137,25 +137,7 @@ export type ConversationMessageBlock = z.infer<
   typeof conversationMessageBlockSchema
 >
 
-export const conversationSnapshotSchema = z
-  .object({
-    id: assistantIdSchema,
-    projectId: assistantIdSchema.optional(),
-    runtimeSelection: agentRuntimeSelectionSchema.optional(),
-    knowledgeRetrievalMode: z.enum(['auto', 'always']).optional(),
-    remote: z
-      .object({
-        channel: projectChannelSchema,
-        accountDisplay: z.string().trim().min(1).max(200),
-        conversationType: z.enum(['direct', 'group'])
-      })
-      .strict()
-      .optional(),
-    title: z.string().trim().min(1).max(200),
-    updatedAt: z.number().int().nonnegative(),
-    messages: z
-      .array(
-        z
+export const conversationMessageSchema = z
   .object({
     id: assistantIdSchema,
     role: z.enum(['user', 'assistant']),
@@ -227,7 +209,29 @@ export const conversationSnapshotSchema = z
       .optional()
   })
   .strict()
-      )
+
+export type ConversationMessage = z.infer<
+  typeof conversationMessageSchema
+>
+
+export const conversationSnapshotSchema = z
+  .object({
+    id: assistantIdSchema,
+    projectId: assistantIdSchema.optional(),
+    runtimeSelection: agentRuntimeSelectionSchema.optional(),
+    knowledgeRetrievalMode: z.enum(['auto', 'always']).optional(),
+    remote: z
+      .object({
+        channel: projectChannelSchema,
+        accountDisplay: z.string().trim().min(1).max(200),
+        conversationType: z.enum(['direct', 'group'])
+      })
+      .strict()
+      .optional(),
+    title: z.string().trim().min(1).max(200),
+    updatedAt: z.number().int().nonnegative(),
+    messages: z
+      .array(conversationMessageSchema)
       .max(500)
   })
   .strict()
@@ -239,6 +243,35 @@ export const conversationSnapshotsSchema = z
   .array(conversationSnapshotSchema)
   .max(100)
 
+export const localConversationHeaderSchema = conversationSnapshotSchema
+  .omit({
+    messages: true,
+    remote: true
+  })
+
+export type LocalConversationHeader = z.infer<
+  typeof localConversationHeaderSchema
+>
+
+export const localConversationSaveSchema = z
+  .object({
+    header: localConversationHeaderSchema,
+    messages: z.array(conversationMessageSchema).max(500)
+  })
+  .strict()
+
+export type LocalConversationSaveInput = z.infer<
+  typeof localConversationSaveSchema
+>
+
+export const localConversationSaveBatchSchema = z
+  .array(localConversationSaveSchema)
+  .max(100)
+
+export type LocalConversationSaveBatch = z.infer<
+  typeof localConversationSaveBatchSchema
+>
+
 export type AssistantProject = ProjectCreateInput & {
   id: string
   kind: ProjectKind

src/shared/contracts.ts

@@ -26,6 +26,7 @@ import {
   type TokenUsageSummary,
   type ConversationSnapshot,
   type ConversationAttachment,
+  type LocalConversationSaveBatch,
   type WorkspaceChanges,
   type WorkspaceDirectoryListing,
   type WorkspaceFilePreview,
@@ -1112,6 +1113,7 @@ export type DesktopApi = {
     close: () => Promise<void>
     isMaximized: () => Promise<boolean>
     onMaximizedChanged: (listener: (maximized: boolean) => void) => () => void
+    onBeforeQuit: (listener: () => Promise<void>) => () => void
     clearLocalData: () => Promise<void>
     onNewConversation: (listener: () => void) => () => void
     onOpenSettings: (listener: () => void) => () => void
@@ -1260,6 +1262,8 @@ export type DesktopApi = {
   conversations: {
     list: () => Promise<ConversationSnapshot[]>
     replace: (conversations: ConversationSnapshot[]) => Promise<void>
+    saveLocal: (batch: LocalConversationSaveBatch) => Promise<void>
+    deleteLocal: (conversationId: string) => Promise<boolean>
     onChanged: (listener: () => void) => () => void
   }
   workspace: {

src/shared/ipc-channels.ts

@@ -7,6 +7,9 @@ export const ipcChannels = {
   windowClose: 'window:close',
   windowIsMaximized: 'window:is-maximized',
   windowMaximizedChanged: 'window:maximized-changed',
+  appRendererPersistenceReady: 'app:renderer-persistence-ready',
+  appRendererPersistenceRequest: 'app:renderer-persistence-request',
+  appRendererPersistenceComplete: 'app:renderer-persistence-complete',
   appClearLocalData: 'app:clear-local-data',
   conversationNew: 'conversation:new',
   settingsOpen: 'settings:open',
@@ -83,6 +86,8 @@ export const ipcChannels = {
   projectsDelete: 'projects:delete',
   conversationsList: 'conversations:list',
   conversationsReplace: 'conversations:replace',
+  conversationsSaveLocal: 'conversations:save-local',
+  conversationsDeleteLocal: 'conversations:delete-local',
   conversationsChanged: 'conversations:changed',
   workspaceChangesGet: 'workspace:changes:get',
   workspaceDirectoryList: 'workspace:directory:list',

tests/performance-regression.manual.test.ts

@@ -0,0 +1,191 @@
+import { mkdtemp, rm, stat } from 'node:fs/promises'
+import { tmpdir } from 'node:os'
+import { join } from 'node:path'
+import { performance } from 'node:perf_hooks'
+import { afterAll, beforeAll, describe, expect, it } from 'vitest'
+import {
+  conversationSnapshotsSchema,
+  localConversationSaveBatchSchema,
+  type ConversationSnapshot,
+  type LocalConversationHeader,
+  type LocalConversationSaveBatch
+} from '../src/shared/assistant-contracts'
+import { AssistantDatabase } from '../src/main/assistant/assistant-database'
+
+const runPerformanceBenchmarks = process.env.GOODBUDDY_PERF === '1'
+const conversationCount = 60
+const messagesPerConversation = 200
+
+let temporaryDirectory = ''
+
+function benchmarkId(value: number): string {
+  return `00000000-0000-4000-8000-${String(value).padStart(12, '0')}`
+}
+
+function createConversations(
+  projectId: string
+): ConversationSnapshot[] {
+  return Array.from({ length: conversationCount }, (_, conversationIndex) => ({
+    id: benchmarkId(conversationIndex + 1),
+    projectId,
+    title: `Conversation ${conversationIndex}`,
+    updatedAt: Date.UTC(2026, 7, 14, 12, conversationIndex),
+    messages: Array.from(
+      { length: messagesPerConversation },
+      (_, messageIndex) => ({
+        id: benchmarkId(
+          1_000_000 +
+            conversationIndex * messagesPerConversation +
+            messageIndex
+        ),
+        role: messageIndex % 2 === 0 ? 'user' as const : 'assistant' as const,
+        content: `Message ${messageIndex} ${'x'.repeat(180)}`,
+        createdAt: Date.UTC(
+          2026,
+          7,
+          14,
+          12,
+          conversationIndex,
+          messageIndex
+        ),
+        state: 'complete' as const
+      })
+    )
+  }))
+}
+
+function measure(operation: () => void): number {
+  const startedAt = performance.now()
+  operation()
+  return performance.now() - startedAt
+}
+
+function localHeader(
+  conversation: ConversationSnapshot
+): LocalConversationHeader {
+  return {
+    id: conversation.id,
+    projectId: conversation.projectId,
+    runtimeSelection: conversation.runtimeSelection,
+    knowledgeRetrievalMode: conversation.knowledgeRetrievalMode,
+    title: conversation.title,
+    updatedAt: conversation.updatedAt
+  }
+}
+
+describe.skipIf(!runPerformanceBenchmarks)(
+  'manual performance regression benchmarks',
+  () => {
+    beforeAll(async () => {
+      temporaryDirectory = await mkdtemp(
+        join(tmpdir(), 'goodbuddy-performance-')
+      )
+    })
+
+    afterAll(async () => {
+      if (temporaryDirectory) {
+        await rm(temporaryDirectory, { recursive: true, force: true })
+      }
+    })
+
+    it('measures conversation persistence and hydration at scale', async () => {
+      const databasePath = join(temporaryDirectory, 'assistant.sqlite')
+      const database = new AssistantDatabase(databasePath)
+      database.initialize('C:\\Workspace')
+      const project = database.listProjects()[0]!
+      const conversations = conversationSnapshotsSchema.parse(
+        createConversations(project.id)
+      )
+
+      const initialReplaceMs = measure(() => {
+        database.replaceConversations(conversations)
+      })
+      const unchangedReplaceMs = measure(() => {
+        database.replaceConversations(conversations)
+      })
+      const updated = conversations.map((conversation, index) =>
+        index === 0
+          ? {
+              ...conversation,
+              updatedAt: conversation.updatedAt + 1,
+              messages: conversation.messages.map((message, messageIndex) =>
+                messageIndex === conversation.messages.length - 1
+                  ? { ...message, content: `${message.content} updated` }
+                  : message
+              )
+            }
+          : conversation
+      )
+      const legacySingleConversationUpdateMs = measure(() => {
+        database.replaceConversations(updated)
+      })
+      const incrementallyUpdated = {
+        ...updated[0]!,
+        updatedAt: updated[0]!.updatedAt + 1,
+        messages: updated[0]!.messages.map((message, messageIndex) =>
+          messageIndex === updated[0]!.messages.length - 1
+            ? { ...message, content: `${message.content} incremental` }
+            : message
+        )
+      }
+      const incrementalBatch: LocalConversationSaveBatch =
+        localConversationSaveBatchSchema.parse([
+          {
+            header: localHeader(incrementallyUpdated),
+            messages: [incrementallyUpdated.messages.at(-1)!]
+          }
+        ])
+      const incrementalSingleMessageMs = measure(() => {
+        database.saveLocalConversations(incrementalBatch)
+      })
+      const metadataOnlyBatch: LocalConversationSaveBatch = [
+        {
+          header: {
+            ...localHeader(incrementallyUpdated),
+            title: 'Incrementally renamed conversation',
+            updatedAt: incrementallyUpdated.updatedAt + 1
+          },
+          messages: []
+        }
+      ]
+      const incrementalMetadataOnlyMs = measure(() => {
+        database.saveLocalConversations(metadataOnlyBatch)
+      })
+      let restored: ConversationSnapshot[] = []
+      const listMs = measure(() => {
+        restored = database.listConversations()
+      })
+      database.close()
+
+      const databaseBytes = (await stat(databasePath)).size
+      const metrics = {
+        conversationCount,
+        messagesPerConversation,
+        totalMessages: conversationCount * messagesPerConversation,
+        initialReplaceMs: Number(initialReplaceMs.toFixed(2)),
+        unchangedReplaceMs: Number(unchangedReplaceMs.toFixed(2)),
+        legacySingleConversationUpdateMs: Number(
+          legacySingleConversationUpdateMs.toFixed(2)
+        ),
+        incrementalSingleMessageMs: Number(
+          incrementalSingleMessageMs.toFixed(2)
+        ),
+        incrementalMetadataOnlyMs: Number(
+          incrementalMetadataOnlyMs.toFixed(2)
+        ),
+        fullSnapshotPayloadBytes: Buffer.byteLength(
+          JSON.stringify(conversations)
+        ),
+        incrementalPayloadBytes: Buffer.byteLength(
+          JSON.stringify(incrementalBatch)
+        ),
+        listMs: Number(listMs.toFixed(2)),
+        databaseBytes
+      }
+      console.log(`PERF_METRICS=${JSON.stringify(metrics)}`)
+
+      expect(restored).toHaveLength(conversationCount)
+      expect(restored[0]?.messages).toHaveLength(messagesPerConversation)
+    }, 30_000)
+  }
+)