diff --git a/docs/features/assistant-workbar/browser-tabs-technical-design.md b/docs/features/assistant-workbar/browser-tabs-technical-design.md
index 4c890cb5..5983d743 100644
--- a/docs/features/assistant-workbar/browser-tabs-technical-design.md
+++ b/docs/features/assistant-workbar/browser-tabs-technical-design.md
@@ -144,12 +144,20 @@ Browser Tab。
 - 没有活动 Conversation 时创建待绑定实例，不创建无归属 Main Browser Context。
 - 主侧栏浏览器快捷按钮优先激活绑定当前 Conversation 的最近使用实例；没有匹配实例时创建
   一个。没有活动 Conversation 时激活最近使用的浏览器实例；完全不存在时创建待绑定实例。
-- 每个实例标题至少区分 Conversation 和当前页面；完整目标通过提示和可访问名称提供。
+- New browser instances use a numbered browser label followed by the active Conversation title, when
+  available. The number avoids existing titles; restoring the layout preserves each saved title.
+  The address bar shows only that instance's page URL. Binding a numbered instance does not overwrite
+  its title; the default unbound browser receives the Conversation label when first bound.
 - 关闭工作栏 Browser Tab 只释放对应 Browser Tab。关闭浏览器上下文是独立危险操作，需要
   明确说明会影响该 Conversation 下的全部 Tab 和 Agent 浏览器状态。
 
 ## 8. 持久化与恢复
 
+`createTab` reuses a live tab only for the same Conversation and workbar instance ID. A new workbar
+instance can adopt the primary tab only when its request creates the Conversation context. An existing
+primary, including one opened by an Agent, is not adopted by a new instance. New sibling tabs start at
+`about:blank` with no navigation history and share the Conversation's cookie partition.
+
 持久化工作栏实例 ID、顺序、自定义标题和公开 Conversation 绑定，不持久化页面进程、CDP
 引用、snapshot、viewport lease、Cookie、Token 或 Main `BrowserTabId`。应用重启后实例显示
 未启动状态，首次导航或 Agent 使用时按原绑定创建新 Tab。
diff --git a/docs/features/assistant-workbar/prd.md b/docs/features/assistant-workbar/prd.md
index b0d68b08..ae097e41 100644
--- a/docs/features/assistant-workbar/prd.md
+++ b/docs/features/assistant-workbar/prd.md
@@ -90,7 +90,7 @@ Runtime
 
 - 应用不得根据当前项目、会话、Runtime、主机或探测结果无提示地增删能力目录项。
 - 用户主动打开、关闭、排序和停靠可关闭的面板实例；任务中心和工作区作为基础工作入口默认
-  存在且不可关闭。不可关闭不等于锁定顺序，排序能力由独立属性控制。
+  存在且不可关闭，分别固定在第一、第二位，排序属性为不可重排。
 - Task Center 是默认跟随当前项目的单实例 Task 索引。每个 Task 只关联一条 Conversation，
   一条 Conversation 可以关联多个 Task；Task Center 不复制会话内容，也不显示普通
   Conversation、Job、Run 或心跳事项。
@@ -369,8 +369,8 @@ Renderer 不接收任意系统 PID 控制能力。控制动作引用 Main 签发
 ### 7.6 工作区
 
 工作区是默认存在、单实例且不可关闭的基础应用。它默认跟随当前项目；项目或目录不可用时
-保留同一 Tab 并显示修复入口，不能通过关闭 Tab 隐藏范围错误。用户仍可调整该 Tab 的顺序，
-除非后续单独引入顺序锁定属性。
+保留同一 Tab 并显示修复入口，不能通过关闭 Tab 隐藏范围错误。任务中心固定在第一位，工作区
+固定在第二位，恢复布局时保持此顺序。
 
 工作区面板允许用户选择：
 
diff --git a/docs/features/assistant-workbar/terminal-tabs-prd.md b/docs/features/assistant-workbar/terminal-tabs-prd.md
index 9f297ad0..de3656a2 100644
--- a/docs/features/assistant-workbar/terminal-tabs-prd.md
+++ b/docs/features/assistant-workbar/terminal-tabs-prd.md
@@ -115,7 +115,7 @@ stdio fallback。首期远程终端随 SSH Channel 结束，不提供跨 SSH 或
 5. 单实例应用已经打开时，再次选择只聚焦已有实例，不创建重复 Tab。
 6. 多实例应用每次选择都创建新实例。
 7. 终端从首期开始就是多实例应用。
-8. 任务中心和工作区保持单实例、默认打开且不可关闭；不可关闭不自动禁止排序。
+8. 任务中心和工作区保持单实例、默认打开且不可关闭，分别固定在第一、第二位，`reorderable` 为 `false`。恢复旧布局时也按此规则修正顺序，其余 Tab 保持相对顺序。
 9. 浏览器注册为可关闭的多实例应用，升级后保留一个默认实例；成果保持单实例、默认打开且
    可关闭。
 10. 用户关闭可关闭实例、切换或重排应用 Tab 后，“+”仍保持可见。
@@ -208,14 +208,18 @@ stdio fallback。首期远程终端随 SSH Channel 结束，不提供跨 SSH 或
 
 | 应用 | 实例策略 | 默认上下文 | 默认打开 | 必须存在 | 可关闭 | 可排序 | 再次从“+”选择 |
 | --- | --- | --- | --- | --- | --- | --- | --- |
-| 任务中心 | `single` | 当前项目 | 是 | 是 | 否 | 是 | 聚焦已有 Tab |
-| 工作区 | `single` | 当前项目 | 是 | 是 | 否 | 是 | 聚焦已有 Tab |
+| 任务中心 | `single` | 当前项目 | 是 | 是 | 否 | 否 | 聚焦已有 Tab |
+| 工作区 | `single` | 当前项目 | 是 | 是 | 否 | 否 | 聚焦已有 Tab |
 | 浏览器 | `multiple` | 当前 Conversation | 是，一个实例 | 否 | 是 | 是 | 每次创建新 Tab |
 | 成果 | `single` | 当前项目 | 是 | 否 | 是 | 是 | 聚焦已有 Tab |
 | 终端 | `multiple` | 当前项目 | 否 | 否 | 是 | 是 | 每次创建新 Tab |
 
 实例策略、默认状态和可关闭策略都是应用注册数据，不能分散硬编码在多个点击处理器中。
 
+新建浏览器使用独立编号标题，避开已有名称；关闭后再次新建也不产生重名。恢复布局保留已保存
+的标题。会话名称用于标识归属，不替代浏览器实例名称。新建页面为空白页，同会话 Cookie 共享
+不表示复用旧页面或导航历史。
+
 ### 7.4 Tab 操作
 
 - 点击或使用方向键切换实例不会暂停或终止后台实例。
diff --git a/src/main/browser/browser-service.test.ts b/src/main/browser/browser-service.test.ts
index c7a9fca1..1aee5533 100644
--- a/src/main/browser/browser-service.test.ts
+++ b/src/main/browser/browser-service.test.ts
@@ -628,6 +628,28 @@ describe('BrowserService', () => {
     await windowLimited.service.dispose()
   })
 
+  it('creates a fresh tab instead of adopting a navigated unowned primary, and restores only the same owner', async () => {
+    const harness = createHarness()
+    const signal = new AbortController().signal
+    try {
+      await harness.service.navigate('conversation', 'https://old.example/', signal, undefined, 21)
+      const [primary] = harness.service.listTabs('conversation', 21)
+      const fresh = await harness.service.createTab('conversation', 21, signal, workbarInstanceId)
+      expect(fresh.tabId).not.toBe(primary!.tabId)
+      expect(fresh.url).toBeUndefined()
+      expect(fresh.canGoBack).toBe(false)
+      expect(harness.slots[1]!.driver.navigate).not.toHaveBeenCalled()
+      await harness.service.navigate('conversation', 'https://new.example/', signal, fresh.tabId, 21)
+      const restored = await harness.service.createTab('conversation', 21, signal, workbarInstanceId)
+      expect(restored.tabId).toBe(fresh.tabId)
+      expect(restored.url).toBe('https://new.example/')
+      expect(harness.service.listTabs('conversation', 21)[0]!.url).toBe('https://old.example/')
+      expect(harness.service.getTabCount('conversation')).toBe(2)
+    } finally {
+      await harness.service.dispose()
+    }
+  })
+
   it('returns one live tab for concurrent requests from the same workbar instance', async () => {
     const gate = deferred<void>()
     const harness = createHarness({ sessionGate: gate.promise })
diff --git a/src/renderer/src/RightAssistantSidebar.resize.test.tsx b/src/renderer/src/RightAssistantSidebar.resize.test.tsx
index 426f417a..19509a02 100644
--- a/src/renderer/src/RightAssistantSidebar.resize.test.tsx
+++ b/src/renderer/src/RightAssistantSidebar.resize.test.tsx
@@ -877,7 +877,7 @@ describe('RightAssistantSidebar resizing', () => {
       workbarInstanceId: expect.any(String)
     })
     expect(browserApi.createTab.mock.calls[1]![0].workbarInstanceId).not.toBe(ownerA)
-    expect(screen.getByRole('tab', { name: '浏览器 · conversation-b' })).toHaveAttribute('aria-selected', 'true')
+    expect(screen.getByRole('tab', { name: '浏览器 1 · conversation-b' })).toHaveAttribute('aria-selected', 'true')
     expect(browserA).toBeVisible()
     await waitFor(() => expect(screen.getByRole('textbox', { name: '浏览器地址' })).toHaveValue('https://b.example/'))
     fireEvent.click(screen.getByRole('button', { name: '前往' }))
@@ -891,6 +891,52 @@ describe('RightAssistantSidebar resizing', () => {
     expect(browserApi.createTab).toHaveBeenCalledTimes(2)
   })
 
+  it('opens a blank browser from + without inheriting the old address or title', async () => {
+    const conversationId = 'old-conversation'
+    renderSidebar({
+      tab: 'browser',
+      activeConversationId: conversationId,
+      browserStates: {
+        [conversationId]: {
+          [firstBrowserTabId]: {
+            ...browserSummary(conversationId, firstBrowserTabId, true),
+            sessionActive: true,
+            url: 'https://old.example/'
+          }
+        }
+      }
+    })
+    await waitFor(() => expect(screen.getByRole('textbox', { name: '浏览器地址' })).toHaveValue('https://old.example/'))
+    fireEvent.click(screen.getByRole('button', { name: '打开工作栏应用' }))
+    fireEvent.click(screen.getByText('浏览器', { selector: 'strong' }).closest('button')!)
+    await waitFor(() => expect(browserApi.createTab).toHaveBeenCalledTimes(2))
+    expect(screen.getByRole('tab', { name: '浏览器 1 · old-conversation' })).toHaveAttribute('aria-selected', 'true')
+    expect(screen.getByRole('textbox', { name: '浏览器地址' })).toHaveValue('')
+    expect(screen.getByRole('button', { name: '返回' })).toBeDisabled()
+    const requests = browserApi.createTab.mock.calls.map(([request]) => request)
+    expect(requests[1]?.workbarInstanceId).not.toBe(requests[0]?.workbarInstanceId)
+    fireEvent.click(screen.getByRole('tab', { name: '浏览器 · old-conversation' }))
+    expect(screen.getByRole('textbox', { name: '浏览器地址' })).toHaveValue('https://old.example/')
+
+    browserApi.createTab.mockImplementation(async ({ conversationId }) =>
+      browserSummary(conversationId, crypto.randomUUID() as BrowserTabId, false)
+    )
+    fireEvent.click(screen.getByRole('button', { name: '打开工作栏应用' }))
+    fireEvent.click(screen.getByText('浏览器', { selector: 'strong' }).closest('button')!)
+    await waitFor(() => expect(browserApi.createTab).toHaveBeenCalledTimes(3))
+    expect(screen.getByRole('tab', { name: '浏览器 2 · old-conversation' })).toHaveAttribute('aria-selected', 'true')
+    fireEvent.click(screen.getByRole('button', { name: '关闭浏览器 1 · old-conversation' }))
+    await waitFor(() => expect(screen.queryByRole('tab', { name: '浏览器 1 · old-conversation' })).not.toBeInTheDocument())
+    fireEvent.click(screen.getByRole('button', { name: '打开工作栏应用' }))
+    fireEvent.click(screen.getByText('浏览器', { selector: 'strong' }).closest('button')!)
+    await waitFor(() => expect(browserApi.createTab).toHaveBeenCalledTimes(4))
+    expect(screen.getByRole('tab', { name: '浏览器 1 · old-conversation' })).toHaveAttribute('aria-selected', 'true')
+    cleanup()
+    renderSidebar({ activeConversationId: conversationId })
+    expect(screen.getByRole('tab', { name: '浏览器 1 · old-conversation' })).toHaveAttribute('aria-selected', 'true')
+    expect(screen.getByRole('tab', { name: '浏览器 2 · old-conversation' })).toBeVisible()
+  })
+
   it('keeps two browser instances independent and closes only the selected Main tab', async () => {
     const conversationId = 'conversation-a'
     const onNavigateBrowser = vi.fn(async () => undefined)
@@ -976,7 +1022,7 @@ describe('RightAssistantSidebar resizing', () => {
     )
 
     fireEvent.click(
-      screen.getByRole('button', { name: /关闭浏览器 · conversation-a · 2/u })
+      screen.getByRole('button', { name: /关闭浏览器 1 · conversation-a/u })
     )
     await waitFor(() =>
       expect(browserApi.closeTab).toHaveBeenCalledWith({
@@ -987,7 +1033,7 @@ describe('RightAssistantSidebar resizing', () => {
     expect(
       screen.getByRole('tab', { name: '浏览器 · conversation-a' })
     ).toBeInTheDocument()
-    expect(screen.queryByRole('tab', { name: /· 2$/u })).not.toBeInTheDocument()
+    expect(screen.queryByRole('tab', { name: '浏览器 1 · conversation-a' })).not.toBeInTheDocument()
   })
 
   it('restores a browser by stable ownership and releases only its viewport lease', async () => {
@@ -1039,7 +1085,7 @@ describe('RightAssistantSidebar resizing', () => {
       expect(browserApi.createTab).not.toHaveBeenCalled()
 
       fireEvent.click(
-        screen.getByRole('tab', { name: `浏览器 · ${conversationId}` })
+        screen.getByRole('tab', { name: '浏览器 · 已恢复' })
       )
       await waitFor(() =>
         expect(browserApi.createTab).toHaveBeenCalledWith({
@@ -1082,7 +1128,7 @@ describe('RightAssistantSidebar resizing', () => {
       ).toBe(false)
 
       fireEvent.click(
-        screen.getByRole('tab', { name: `浏览器 · ${conversationId}` })
+        screen.getByRole('tab', { name: '浏览器 · 已恢复' })
       )
       await waitFor(() => {
         const acquisitions = browserApi.setViewport.mock.calls
@@ -1097,7 +1143,7 @@ describe('RightAssistantSidebar resizing', () => {
       cleanup()
       renderSidebar({ activeConversationId: 'different-conversation' })
       fireEvent.click(
-        screen.getByRole('tab', { name: `浏览器 · ${conversationId}` })
+        screen.getByRole('tab', { name: '浏览器 · 已恢复' })
       )
       await waitFor(() => expect(browserApi.createTab).toHaveBeenCalledTimes(2))
       expect(browserApi.createTab).toHaveBeenLastCalledWith({
diff --git a/src/renderer/src/RightAssistantSidebar.tsx b/src/renderer/src/RightAssistantSidebar.tsx
index 57b9a98a..195d5858 100644
--- a/src/renderer/src/RightAssistantSidebar.tsx
+++ b/src/renderer/src/RightAssistantSidebar.tsx
@@ -710,13 +710,15 @@ export function RightAssistantSidebar({
           ...instance,
           ...(conversationId
             ? {
-                title: `${label} · ${conversationTitles.get(conversationId) ?? conversationId}`,
+                title: initialLayout
+                  ? instance.title
+                  : `${label} · ${conversationTitles.get(conversationId) ?? conversationId}`,
                 targetRef: {
                   type: 'conversation' as const,
                   conversationId
                 }
               }
-            : { title: `${label} · ${t('sidebar.browser.unbound')}` })
+            : { title: initialLayout ? instance.title : `${label} · ${t('sidebar.browser.unbound')}` })
         }
       }
     )
@@ -1055,26 +1057,23 @@ export function RightAssistantSidebar({
               conversationId: activeConversationId
             }
           : undefined
-      const sameConversationBrowsers = conversationTarget
-        ? workbarInstances.filter(
-            (candidate) =>
-              candidate.appId === 'browser' &&
-              candidate.targetRef?.type === 'conversation' &&
-              candidate.targetRef.conversationId ===
-                conversationTarget.conversationId
-          ).length
-        : 0
       const conversationTitle = activeConversationId
         ? conversationTitles.get(activeConversationId) ?? activeConversationId
         : undefined
+      let browserNumber = 1
+      const browserTitle = (): string =>
+        `${definition.label} ${browserNumber}${conversationTitle ? ` · ${conversationTitle}` : ''}`
+      while (workbarInstances.some((candidate) => candidate.title === browserTitle())) {
+        browserNumber += 1
+      }
       const instance: WorkbarTabInstance = {
         id: crypto.randomUUID(),
         appId: request.appId,
         title:
           request.appId === 'terminal'
             ? `${definition.label} ${sameTargetTerminals + 1}`
-            : request.appId === 'browser' && conversationTitle
-              ? `${definition.label} · ${conversationTitle}${sameConversationBrowsers > 0 ? ` · ${sameConversationBrowsers + 1}` : ''}`
+            : request.appId === 'browser'
+              ? browserTitle()
             : definition.label,
         ...(request.targetRef || conversationTarget
           ? { targetRef: request.targetRef ?? conversationTarget }
@@ -1124,14 +1123,14 @@ export function RightAssistantSidebar({
           throw new Error(t('sidebar.errors.browserControlUnavailable'))
         }
         if (instance.targetRef?.type !== 'conversation') {
-          const conversationTitle =
-            conversationTitles.get(conversationId) ?? conversationId
           setWorkbarInstances((current) =>
             current.map((candidate) =>
               candidate.id === instance.id
                 ? {
                     ...candidate,
-                    title: `${t('sidebar.tabs.browser.label')} · ${conversationTitle}`,
+                    ...(candidate.id === DEFAULT_WORKBAR_INSTANCES.find((item) => item.appId === 'browser')?.id
+                      ? { title: `${t('sidebar.tabs.browser.label')} · ${conversationTitles.get(conversationId) ?? conversationId}` }
+                      : {}),
                     targetRef: { type: 'conversation', conversationId }
                   }
                 : candidate
@@ -1895,7 +1894,7 @@ export function RightAssistantSidebar({
                       </span>
                       <span>
                         {schedule
-                          ? t(`task.mode.${schedule.workMode}`)
+                          ? t('task.mode.conversation')
                           : task.workMode
                             ? t(`task.mode.${task.workMode}`)
                             : t('task.mode.unavailable')}
diff --git a/src/renderer/src/WorkbarShell.test.tsx b/src/renderer/src/WorkbarShell.test.tsx
index edf5d76e..bdc1bdc2 100644
--- a/src/renderer/src/WorkbarShell.test.tsx
+++ b/src/renderer/src/WorkbarShell.test.tsx
@@ -104,6 +104,8 @@ describe('WorkbarShell', () => {
       name: '已打开的工作栏应用'
     })
     expect(within(tablist).getAllByRole('tab')).toHaveLength(4)
+    expect(within(tablist).getAllByRole('tab').map((tab) => tab.textContent))
+      .toEqual(DEFAULT_WORKBAR_INSTANCES.map((instance) => instance.title))
     expect(
       within(tablist).queryByRole('button', {
         name: '打开工作栏应用'
@@ -123,6 +125,27 @@ describe('WorkbarShell', () => {
     ).not.toHaveClass('workbar-shell__tab-item--active')
   })
 
+  it('pins tasks and workspace in supplied layouts and navigates in displayed order', () => {
+    const [tasks, workspace, browser, results] = DEFAULT_WORKBAR_INSTANCES
+    render(
+      <ControlledShell
+        initialInstances={[terminalOne, workspace!, results!, tasks!, browser!]}
+      />
+    )
+
+    const tabs = screen.getAllByRole('tab')
+    expect(tabs.map((tab) => tab.textContent)).toEqual(
+      [tasks!, workspace!, terminalOne, results!, browser!].map((instance) => instance.title)
+    )
+    expect(tabs[2]).toHaveAttribute('aria-selected', 'true')
+    fireEvent.keyDown(tabs[2]!, { key: 'Home' })
+    expect(tabs[0]).toHaveFocus()
+    fireEvent.keyDown(tabs[0]!, { key: 'ArrowRight' })
+    expect(tabs[1]).toHaveFocus()
+    fireEvent.keyDown(tabs[1]!, { key: 'ArrowRight' })
+    expect(tabs[2]).toHaveFocus()
+  })
+
   it('does not expose close controls for fixed tabs', () => {
     render(<ControlledShell />)
 
diff --git a/src/renderer/src/WorkbarShell.tsx b/src/renderer/src/WorkbarShell.tsx
index afd456eb..95616b1c 100644
--- a/src/renderer/src/WorkbarShell.tsx
+++ b/src/renderer/src/WorkbarShell.tsx
@@ -20,6 +20,7 @@ import { useTranslation } from 'react-i18next'
 import {
   WORKBAR_APP_DEFINITIONS,
   WORKBAR_LIMITS,
+  orderWorkbarInstances,
   type WorkbarAppDefinition,
   type WorkbarAppId,
   type WorkbarTabInstance,
@@ -102,7 +103,7 @@ export function WorkbarShell({
   activeInstanceId,
   appDefinitions = WORKBAR_APP_DEFINITIONS,
   className,
-  instances,
+  instances: unorderedInstances,
   onActiveInstanceChange,
   onCloseInstance,
   onCreateInstance,
@@ -111,6 +112,7 @@ export function WorkbarShell({
   renderPanel,
   renderTabAdornment
 }: WorkbarShellProps): React.JSX.Element {
+  const instances = orderWorkbarInstances(unorderedInstances)
   const { t } = useTranslation('workspace')
   const idPrefix = useId()
   const addButtonRef = useRef<HTMLButtonElement>(null)
diff --git a/src/renderer/src/i18n/locales/en-US/workspace.ts b/src/renderer/src/i18n/locales/en-US/workspace.ts
index 1765666f..d6525b02 100644
--- a/src/renderer/src/i18n/locales/en-US/workspace.ts
+++ b/src/renderer/src/i18n/locales/en-US/workspace.ts
@@ -435,6 +435,7 @@ export const workspace = {
       interrupted: 'Interrupted'
     },
     mode: {
+      conversation: 'Conversation settings',
       ask: 'Ask',
       execute: 'Execute',
       unavailable: 'Mode unavailable'
diff --git a/src/renderer/src/i18n/locales/zh-CN/workspace.ts b/src/renderer/src/i18n/locales/zh-CN/workspace.ts
index bdc45278..8ac652d5 100644
--- a/src/renderer/src/i18n/locales/zh-CN/workspace.ts
+++ b/src/renderer/src/i18n/locales/zh-CN/workspace.ts
@@ -424,6 +424,7 @@ export const workspace = {
       interrupted: '已中断'
     },
     mode: {
+      conversation: '跟随会话设置',
       ask: 'Ask',
       execute: 'Execute',
       unavailable: '模式不可用'
diff --git a/src/shared/workbar-contracts.test.ts b/src/shared/workbar-contracts.test.ts
index 0e0d148c..6291bfbb 100644
--- a/src/shared/workbar-contracts.test.ts
+++ b/src/shared/workbar-contracts.test.ts
@@ -25,8 +25,8 @@ describe('workbar contracts', () => {
         reorderable
       }))
     ).toEqual([
-      { id: 'tasks', instancePolicy: 'single', defaultContext: 'current-project', defaultOpen: true, required: true, closable: false, reorderable: true },
-      { id: 'workspace', instancePolicy: 'single', defaultContext: 'current-project', defaultOpen: true, required: true, closable: false, reorderable: true },
+      { id: 'tasks', instancePolicy: 'single', defaultContext: 'current-project', defaultOpen: true, required: true, closable: false, reorderable: false },
+      { id: 'workspace', instancePolicy: 'single', defaultContext: 'current-project', defaultOpen: true, required: true, closable: false, reorderable: false },
       { id: 'browser', instancePolicy: 'multiple', defaultContext: 'current-conversation', defaultOpen: true, required: false, closable: true, reorderable: true },
       { id: 'results', instancePolicy: 'single', defaultContext: 'current-project', defaultOpen: true, required: false, closable: true, reorderable: true },
       {
@@ -209,14 +209,46 @@ describe('workbar contracts', () => {
     expect(normalized?.instances.map(({ id, appId }) => ({ id, appId })))
       .toEqual([
         { id: taskId, appId: 'tasks' },
+        { id: workspaceId, appId: 'workspace' },
         { id: browserId, appId: 'browser' },
-        { id: secondBrowserId, appId: 'browser' },
-        { id: workspaceId, appId: 'workspace' }
+        { id: secondBrowserId, appId: 'browser' }
       ])
     expect(normalized?.activeInstanceId).toBe(taskId)
     expect(normalized?.taskScope).toBe('all-projects')
   })
 
+  it('pins restored tasks and workspace without changing other order or selection', () => {
+    const workspace = {
+      id: '00000000-0000-4000-8000-000000000105',
+      appId: 'workspace', title: 'Workspace'
+    } as const
+    const tasks = { id: taskId, appId: 'tasks', title: 'Tasks' } as const
+    const terminal = {
+      id: terminalId, appId: 'terminal', title: 'Terminal',
+      targetRef: { type: 'local' }
+    } as const
+    const browser = {
+      id: '00000000-0000-4000-8000-000000000103',
+      appId: 'browser', title: 'Browser',
+      targetRef: { type: 'conversation', conversationId: 'conversation-a' }
+    } as const
+    const layout = {
+      instances: [terminal, workspace, browser, tasks],
+      activeInstanceId: browser.id,
+      expanded: true, dock: 'right', widthRatio: 0.4,
+      taskScope: 'all-projects'
+    } as const
+
+    const normalized = normalizeWorkbarLayoutPreferences(layout, [tasks, workspace])
+    expect(normalized).toEqual({
+      ...layout,
+      instances: [tasks, workspace, terminal, browser]
+    })
+    expect(layout.instances).toEqual([terminal, workspace, browser, tasks])
+    expect(normalizeWorkbarLayoutPreferences(normalized, [tasks, workspace]))
+      .toEqual(normalized)
+  })
+
   it('preserves a valid empty layout with a null active instance', () => {
     expect(
       normalizeWorkbarLayoutPreferences(
diff --git a/src/shared/workbar-contracts.ts b/src/shared/workbar-contracts.ts
index 88cf6afb..aecdc244 100644
--- a/src/shared/workbar-contracts.ts
+++ b/src/shared/workbar-contracts.ts
@@ -107,7 +107,7 @@ export const WORKBAR_APP_DEFINITIONS = [
     defaultOpen: true,
     required: true,
     closable: false,
-    reorderable: true,
+    reorderable: false,
     availability: { state: 'available' }
   },
   {
@@ -121,7 +121,7 @@ export const WORKBAR_APP_DEFINITIONS = [
     defaultOpen: true,
     required: true,
     closable: false,
-    reorderable: true,
+    reorderable: false,
     availability: { state: 'available' }
   },
   {
@@ -317,6 +317,18 @@ export type WorkbarLayoutPreferences = z.infer<
   typeof workbarLayoutPreferencesSchema
 >
 
+export function orderWorkbarInstances(
+  instances: readonly WorkbarTabInstance[]
+): WorkbarTabInstance[] {
+  return [
+    ...instances.filter((instance) => instance.appId === 'tasks'),
+    ...instances.filter((instance) => instance.appId === 'workspace'),
+    ...instances.filter(
+      (instance) => instance.appId !== 'tasks' && instance.appId !== 'workspace'
+    )
+  ]
+}
+
 export function normalizeWorkbarLayoutPreferences(
   value: unknown,
   defaultInstances: readonly WorkbarTabInstance[]
@@ -374,7 +386,7 @@ export function normalizeWorkbarLayoutPreferences(
     )
   }
 
-  const boundedInstances = instances.slice(
+  const boundedInstances = orderWorkbarInstances(instances).slice(
     0,
     WORKBAR_LIMITS.maximumOpenInstances
   )
diff --git a/tests/browser-tabs-electron-e2e.ts b/tests/browser-tabs-electron-e2e.ts
index 001819b6..718cc08b 100644
--- a/tests/browser-tabs-electron-e2e.ts
+++ b/tests/browser-tabs-electron-e2e.ts
@@ -1,6 +1,6 @@
 import assert from 'node:assert/strict'
 import { createServer } from 'node:http'
-import { app, BrowserWindow } from 'electron'
+import { app, BrowserWindow, webContents } from 'electron'
 import { Client } from '@modelcontextprotocol/sdk/client/index.js'
 import { StreamableHTTPClientTransport } from '@modelcontextprotocol/sdk/client/streamableHttp.js'
 import type { KnowledgeService } from '../src/main/knowledge/knowledge-service'
@@ -13,7 +13,7 @@ const firstWorkbarId = '00000000-0000-4000-8000-000000000901'
 const secondWorkbarId = '00000000-0000-4000-8000-000000000902'
 
 function page(title: string, body = ''): string {
-  return `<!doctype html><html><body><h1>${title}</h1>${body}</body></html>`
+  return `<!doctype html><html><head><title>${title}</title></head><body><h1>${title}</h1>${body}</body></html>`
 }
 
 async function main(): Promise<void> {
@@ -50,12 +50,22 @@ async function main(): Promise<void> {
   let client: Client | undefined
   let token: string | undefined
   try {
+    await browser.navigate(conversationId, `${origin}/first`, controller.signal, undefined, window.webContents.id)
+    const [unownedPrimary] = browser.listTabs(conversationId, window.webContents.id)
+    assert(unownedPrimary)
     const first = await browser.createTab(
       conversationId,
       window.webContents.id,
       controller.signal,
       firstWorkbarId
     )
+    assert.notEqual(first.tabId, unownedPrimary.tabId)
+    assert.equal(first.url, undefined)
+    assert.match(JSON.stringify(await browser.snapshot(conversationId, controller.signal, unownedPrimary.tabId, window.webContents.id)), /First tab/u)
+    await browser.closeTab(conversationId, unownedPrimary.tabId, window.webContents.id)
+    console.log('New workbar ID did not adopt the existing navigated primary')
+    await browser.navigate(conversationId, `${origin}/first`, controller.signal, first.tabId, window.webContents.id)
+    const existingContents = new Set(webContents.getAllWebContents().map((contents) => contents.id))
     const second = await browser.createTab(
       conversationId,
       window.webContents.id,
@@ -63,8 +73,15 @@ async function main(): Promise<void> {
       secondWorkbarId
     )
     assert.notEqual(first.tabId, second.tabId)
+    assert.equal(second.url, undefined)
+    assert.equal(second.canGoBack, false)
+    const freshContents = webContents.getAllWebContents().filter((contents) => !existingContents.has(contents.id))
+    assert.equal(freshContents.length, 1)
+    assert.equal(freshContents[0]!.getURL(), 'about:blank')
+    assert.equal(freshContents[0]!.getTitle(), 'about:blank')
+    assert.equal(freshContents[0]!.navigationHistory.canGoBack(), false)
+    console.log('Fresh WebContents verified: about:blank, blank-page title, no history')
 
-    await browser.navigate(conversationId, `${origin}/first`, controller.signal, first.tabId, window.webContents.id)
     await browser.navigate(conversationId, `${origin}/second`, controller.signal, second.tabId, window.webContents.id)
     assert.match(JSON.stringify(await browser.snapshot(conversationId, controller.signal, first.tabId, window.webContents.id)), /First tab/u)
     assert.match(JSON.stringify(await browser.snapshot(conversationId, controller.signal, second.tabId, window.webContents.id)), /Second tab/u)
@@ -72,6 +89,7 @@ async function main(): Promise<void> {
     await browser.navigate(conversationId, `${origin}/set-cookie`, controller.signal, first.tabId, window.webContents.id)
     await browser.navigate(conversationId, `${origin}/cookie`, controller.signal, second.tabId, window.webContents.id)
     assert.match(JSON.stringify(await browser.snapshot(conversationId, controller.signal, second.tabId, window.webContents.id)), /shared-browser-tab=visible/u)
+    console.log('Independent pages and shared conversation cookies verified')
 
     await gateway.start()
     const usage = browser.acquireTabUsage(conversationId, first.tabId, 'electron-e2e', window.webContents.id)