diff --git a/desktop/src/components/browser/BrowserAddressBar.test.tsx b/desktop/src/components/browser/BrowserAddressBar.test.tsx
index e6c6cc3a..7db901b0 100644
--- a/desktop/src/components/browser/BrowserAddressBar.test.tsx
+++ b/desktop/src/components/browser/BrowserAddressBar.test.tsx
@@ -1,5 +1,5 @@
-import { fireEvent, render, screen } from '@testing-library/react'
-import { describe, expect, it, vi } from 'vitest'
+import { cleanup, fireEvent, render, screen } from '@testing-library/react'
+import { afterEach, describe, expect, it, vi } from 'vitest'
 import '@testing-library/jest-dom'
 import { BrowserAddressBar } from './BrowserAddressBar'
 
@@ -8,6 +8,10 @@ const baseProps = {
   onNavigate: vi.fn(), onBack: vi.fn(), onForward: vi.fn(), onReload: vi.fn(),
 }
 
+afterEach(() => {
+  cleanup()
+})
+
 describe('BrowserAddressBar', () => {
   it('shows the current url in the input', () => {
     render(<BrowserAddressBar {...baseProps} />)
@@ -23,6 +27,36 @@ describe('BrowserAddressBar', () => {
     expect(onNavigate).toHaveBeenCalledWith('http://localhost:3000/x')
   })
 
+  it('submits an empty address as empty', () => {
+    const onNavigate = vi.fn()
+    render(<BrowserAddressBar {...baseProps} url="" onNavigate={onNavigate} />)
+    fireEvent.submit(screen.getByRole('textbox').closest('form')!)
+    expect(onNavigate).toHaveBeenCalledWith('')
+  })
+
+  it('normalizes localhost and bare domains before navigating', () => {
+    const onNavigate = vi.fn()
+    render(<BrowserAddressBar {...baseProps} url="" onNavigate={onNavigate} />)
+    const input = screen.getByRole('textbox')
+
+    fireEvent.change(input, { target: { value: 'localhost:3000' } })
+    fireEvent.submit(input.closest('form')!)
+    fireEvent.change(input, { target: { value: 'example.com' } })
+    fireEvent.submit(input.closest('form')!)
+
+    expect(onNavigate).toHaveBeenNthCalledWith(1, 'http://localhost:3000')
+    expect(onNavigate).toHaveBeenNthCalledWith(2, 'https://example.com')
+  })
+
+  it('preserves explicit URL schemes', () => {
+    const onNavigate = vi.fn()
+    render(<BrowserAddressBar {...baseProps} url="" onNavigate={onNavigate} />)
+    const input = screen.getByRole('textbox')
+    fireEvent.change(input, { target: { value: 'about:blank' } })
+    fireEvent.submit(input.closest('form')!)
+    expect(onNavigate).toHaveBeenCalledWith('about:blank')
+  })
+
   it('disables back when cannot go back', () => {
     render(<BrowserAddressBar {...baseProps} canGoBack={false} />)
     expect(screen.getByLabelText('后退')).toBeDisabled()
diff --git a/desktop/src/components/browser/BrowserAddressBar.tsx b/desktop/src/components/browser/BrowserAddressBar.tsx
index 05b34095..4b9676e1 100644
--- a/desktop/src/components/browser/BrowserAddressBar.tsx
+++ b/desktop/src/components/browser/BrowserAddressBar.tsx
@@ -23,11 +23,12 @@ export function BrowserAddressBar({ url, canGoBack, canGoForward, loading = fals
       <button aria-label="刷新" aria-busy={loading} onClick={onReload} className="p-1">
         {loading ? <Loader2 size={16} className="animate-spin" /> : <RotateCw size={16} />}
       </button>
-      <form className="flex-1" onSubmit={(e) => { e.preventDefault(); onNavigate(draft.trim()) }}>
+      <form className="flex-1" onSubmit={(e) => { e.preventDefault(); onNavigate(normalizeBrowserAddress(draft)) }}>
         <input
           className="w-full rounded-md bg-[var(--color-surface)] px-2 py-1 text-xs text-[var(--color-text-primary)]"
           value={draft}
           onChange={(e) => setDraft(e.target.value)}
+          placeholder="输入网址..."
           spellCheck={false}
         />
       </form>
@@ -42,3 +43,13 @@ export function BrowserAddressBar({ url, canGoBack, canGoForward, loading = fals
     </div>
   )
 }
+
+export function normalizeBrowserAddress(input: string): string {
+  const value = input.trim()
+  if (!value) return ''
+  if (/^[a-z][a-z\d+\-.]*:\/\//i.test(value) || /^(about|data|file):/i.test(value)) return value
+  if (/^(localhost|127(?:\.\d{1,3}){3}|\[::1\]|::1)(?::\d+)?(?:[/?#].*)?$/i.test(value)) {
+    return `http://${value}`
+  }
+  return `https://${value}`
+}
diff --git a/desktop/src/components/browser/BrowserSurface.test.tsx b/desktop/src/components/browser/BrowserSurface.test.tsx
index c92e0175..62426573 100644
--- a/desktop/src/components/browser/BrowserSurface.test.tsx
+++ b/desktop/src/components/browser/BrowserSurface.test.tsx
@@ -1,9 +1,12 @@
 import '@testing-library/jest-dom'
-import { act, fireEvent, render, screen } from '@testing-library/react'
+import { act, cleanup, fireEvent, render, screen } from '@testing-library/react'
 import { afterEach, beforeAll, describe, expect, it, vi } from 'vitest'
 
 beforeAll(() => {
-  globalThis.ResizeObserver = class { observe() {} unobserve() {} disconnect() {} } as unknown as typeof ResizeObserver
+  Object.defineProperty(globalThis, 'ResizeObserver', {
+    configurable: true,
+    value: class { observe() {} unobserve() {} disconnect() {} },
+  })
 })
 
 const { bridge } = vi.hoisted(() => ({
@@ -18,6 +21,7 @@ import { useWorkspacePanelStore } from '../../stores/workspacePanelStore'
 import { useOverlayStore } from '../../stores/overlayStore'
 
 afterEach(() => {
+  cleanup()
   Object.values(bridge).forEach((f) => f.mockReset())
   useBrowserPanelStore.setState(useBrowserPanelStore.getInitialState(), true)
   // browserPanelStore.open() now also opens the unified workbench; keep it isolated.
@@ -32,6 +36,23 @@ describe('BrowserSurface', () => {
     expect(bridge.open).toHaveBeenCalledWith('http://localhost:5173/', expect.objectContaining({ width: expect.any(Number) }))
   })
 
+  it('renders an empty address bar without opening a preview for a blank session', () => {
+    useBrowserPanelStore.getState().ensureBlank('s1')
+    render(<BrowserSurface sessionId="s1" />)
+    expect(screen.getByRole('textbox')).toHaveValue('')
+    expect(bridge.open).not.toHaveBeenCalled()
+  })
+
+  it('first navigation from a blank session opens the native preview', () => {
+    useBrowserPanelStore.getState().ensureBlank('s1')
+    render(<BrowserSurface sessionId="s1" />)
+    const input = screen.getByRole('textbox')
+    fireEvent.change(input, { target: { value: 'localhost:3000' } })
+    fireEvent.submit(input.closest('form')!)
+    expect(bridge.open).toHaveBeenCalledWith('http://localhost:3000', expect.objectContaining({ width: expect.any(Number) }))
+    expect(bridge.navigate).not.toHaveBeenCalled()
+  })
+
   it('navigating via address bar calls store + bridge', () => {
     useBrowserPanelStore.getState().open('s1', 'http://localhost:5173/')
     render(<BrowserSurface sessionId="s1" />)
diff --git a/desktop/src/components/browser/BrowserSurface.tsx b/desktop/src/components/browser/BrowserSurface.tsx
index 71473801..73221b56 100644
--- a/desktop/src/components/browser/BrowserSurface.tsx
+++ b/desktop/src/components/browser/BrowserSurface.tsx
@@ -21,7 +21,7 @@ export function BrowserSurface({ sessionId }: { sessionId: string }) {
 
   useLayoutEffect(() => {
     const el = hostRef.current
-    if (!el || !session) return
+    if (!el || !session?.url) return
     previewBridge.open(session.url, computeWebviewBounds(el.getBoundingClientRect()))
     // The visibility-sync effect below owns setVisible() — including the
     // initial reveal — so it always factors in overlayCount.
@@ -70,6 +70,22 @@ export function BrowserSurface({ sessionId }: { sessionId: string }) {
 
   if (!session) return null
 
+  const openOrNavigate = (url: string) => {
+    if (!url) return
+    const current = useBrowserPanelStore.getState().bySession[sessionId]
+    store.navigate(sessionId, url)
+    if (current?.url) {
+      previewBridge.navigate(url)
+      return
+    }
+    const el = hostRef.current
+    if (el) {
+      previewBridge.open(url, computeWebviewBounds(el.getBoundingClientRect()))
+    } else {
+      previewBridge.navigate(url)
+    }
+  }
+
   return (
     <div className="flex h-full flex-col">
       <BrowserAddressBar
@@ -77,10 +93,14 @@ export function BrowserSurface({ sessionId }: { sessionId: string }) {
         canGoBack={session.canGoBack}
         canGoForward={session.canGoForward}
         loading={session.loading}
-        onNavigate={(url) => { store.navigate(sessionId, url); previewBridge.navigate(url) }}
+        onNavigate={openOrNavigate}
         onBack={() => { store.goBack(sessionId); store.setLoading(sessionId, true); previewBridge.navigate(useBrowserPanelStore.getState().bySession[sessionId]!.url) }}
         onForward={() => { store.goForward(sessionId); store.setLoading(sessionId, true); previewBridge.navigate(useBrowserPanelStore.getState().bySession[sessionId]!.url) }}
-        onReload={() => { store.setLoading(sessionId, true); previewBridge.navigate(session.url) }}
+        onReload={() => {
+          if (!session.url) return
+          store.setLoading(sessionId, true)
+          previewBridge.navigate(session.url)
+        }}
       />
       <div className="flex items-center gap-1 border-b px-2 py-1">
         <button
diff --git a/desktop/src/components/chat/CurrentTurnChangeCard.test.tsx b/desktop/src/components/chat/CurrentTurnChangeCard.test.tsx
index 3dacbd69..ef3c66cc 100644
--- a/desktop/src/components/chat/CurrentTurnChangeCard.test.tsx
+++ b/desktop/src/components/chat/CurrentTurnChangeCard.test.tsx
@@ -1,6 +1,6 @@
 import '@testing-library/jest-dom'
-import { describe, expect, it, vi, beforeEach } from 'vitest'
-import { render, screen, fireEvent } from '@testing-library/react'
+import { describe, expect, it, vi, beforeEach, afterEach } from 'vitest'
+import { render, screen, fireEvent, cleanup } from '@testing-library/react'
 import { act } from 'react'
 
 // ──────────────────────────────────────────────────────────────────────────────
@@ -126,6 +126,10 @@ function renderCard(filesChanged: string[]) {
 // ──────────────────────────────────────────────────────────────────────────────
 // Tests
 // ──────────────────────────────────────────────────────────────────────────────
+afterEach(() => {
+  cleanup()
+})
+
 describe('CurrentTurnChangeCard – rich file row (icon / name / type)', () => {
   beforeEach(() => {
     vi.clearAllMocks()
@@ -222,6 +226,13 @@ describe('CurrentTurnChangeCard – open-with buttons', () => {
     expect(screen.getAllByRole('button', { name: 'openWith.title' })).toHaveLength(2)
   })
 
+  it('hides the workspace chevron on rows that already show an open-with button', () => {
+    renderCard(['/w/proj/README.md', '/w/proj/index.html', '/w/proj/src/main.ts'])
+
+    expect(screen.getAllByRole('button', { name: 'openWith.title' })).toHaveLength(2)
+    expect(screen.getAllByText('chevron_right')).toHaveLength(1)
+  })
+
   it('clicking README.md open-with opens menu with workspace preview item', async () => {
     renderCard(['/w/proj/README.md'])
     const [openWithBtn] = screen.getAllByRole('button', { name: 'openWith.title' })
diff --git a/desktop/src/components/chat/CurrentTurnChangeCard.tsx b/desktop/src/components/chat/CurrentTurnChangeCard.tsx
index 27d29460..47cddda2 100644
--- a/desktop/src/components/chat/CurrentTurnChangeCard.tsx
+++ b/desktop/src/components/chat/CurrentTurnChangeCard.tsx
@@ -157,7 +157,9 @@ export function CurrentTurnChangeCard({
                   <span className="block truncate text-sm font-medium text-[var(--color-text-primary)]">{fileName}</span>
                   <span className="block truncate text-xs text-[var(--color-text-tertiary)]">{`${t(typeInfo.categoryKey as Parameters<typeof t>[0])} · ${typeInfo.ext}`}</span>
                 </span>
-                <span className="material-symbols-outlined shrink-0 text-[18px] text-[var(--color-text-tertiary)]">chevron_right</span>
+                {!previewable && (
+                  <span className="material-symbols-outlined shrink-0 text-[18px] text-[var(--color-text-tertiary)]">chevron_right</span>
+                )}
               </button>
               {previewable && (
                 <button
diff --git a/desktop/src/components/layout/TabBar.test.tsx b/desktop/src/components/layout/TabBar.test.tsx
index 424de3b0..b84dc9d0 100644
--- a/desktop/src/components/layout/TabBar.test.tsx
+++ b/desktop/src/components/layout/TabBar.test.tsx
@@ -784,12 +784,10 @@ describe('TabBar', () => {
     expect(useWorkspacePanelStore.getState().isPanelOpen('tab-1')).toBe(false)
   })
 
-  it('toggles the unified workbench in browser mode for the active session from the toolbar', async () => {
+  it('does not render a browser toolbar button for session tabs', async () => {
     const { TabBar } = await import('./TabBar')
     const { useTabStore } = await import('../../stores/tabStore')
     const { useChatStore } = await import('../../stores/chatStore')
-    const { useBrowserPanelStore } = await import('../../stores/browserPanelStore')
-    const { useWorkspacePanelStore } = await import('../../stores/workspacePanelStore')
 
     useTabStore.setState({
       tabs: [
@@ -806,16 +804,8 @@ describe('TabBar', () => {
       render(<TabBar />)
     })
 
-    // Opening the browser surfaces the shared workbench in browser mode.
-    fireEvent.click(screen.getByRole('button', { name: 'Show Browser' }))
-    expect(useBrowserPanelStore.getState().bySession['tab-1']?.isOpen).toBe(true)
-    expect(useWorkspacePanelStore.getState().isPanelOpen('tab-1')).toBe(true)
-    expect(useWorkspacePanelStore.getState().getMode('tab-1')).toBe('browser')
-
-    // Toggling it off closes the unified panel (browser state is retained in its store).
-    fireEvent.click(screen.getByRole('button', { name: 'Hide Browser' }))
-    expect(useWorkspacePanelStore.getState().isPanelOpen('tab-1')).toBe(false)
-    expect(screen.getByRole('button', { name: 'Show Browser' })).toBeInTheDocument()
+    expect(screen.queryByRole('button', { name: 'Show Browser' })).not.toBeInTheDocument()
+    expect(screen.queryByRole('button', { name: 'Hide Browser' })).not.toBeInTheDocument()
   })
 
   it('hides the browser toolbar button for non-session tabs', async () => {
diff --git a/desktop/src/components/layout/TabBar.tsx b/desktop/src/components/layout/TabBar.tsx
index 70d502b9..72a42b9f 100644
--- a/desktop/src/components/layout/TabBar.tsx
+++ b/desktop/src/components/layout/TabBar.tsx
@@ -11,11 +11,10 @@ import { useChatStore } from '../../stores/chatStore'
 import { useSessionStore } from '../../stores/sessionStore'
 import { useWorkspacePanelStore } from '../../stores/workspacePanelStore'
 import { useTerminalPanelStore } from '../../stores/terminalPanelStore'
-import { useBrowserPanelStore } from '../../stores/browserPanelStore'
 import { useTranslation } from '../../i18n'
 import { WindowControls, showWindowControls } from './WindowControls'
 import { OpenProjectMenu } from './OpenProjectMenu'
-import { Folder, FolderOpen, Globe, SquareTerminal } from 'lucide-react'
+import { Folder, FolderOpen, SquareTerminal } from 'lucide-react'
 import { ActionDialog } from '../shared/ActionDialog'
 
 const TAB_WIDTH = 180
@@ -73,7 +72,6 @@ export function TabBar() {
     activeTabId && isActiveSessionTab ? state.getMode(activeTabId) : 'workspace',
   )
   const isWorkspacePanelOpen = isWorkbenchOpen && workbenchMode === 'workspace'
-  const isBrowserPanelOpen = isWorkbenchOpen && workbenchMode === 'browser'
   const isTerminalPanelOpen = useTerminalPanelStore((state) =>
     activeTabId && isActiveSessionTab ? state.isPanelOpen(activeTabId) : false,
   )
@@ -406,30 +404,6 @@ export function TabBar() {
             active={isWorkspacePanelOpen}
           />
         )}
-        {isActiveSessionTab && activeTabId && (
-          <ToolbarIconButton
-            icon={<Globe size={17} strokeWidth={1.9} />}
-            label={t(isBrowserPanelOpen ? 'tabs.hideBrowser' : 'tabs.showBrowser')}
-            onClick={() => {
-              const workbench = useWorkspacePanelStore.getState()
-              if (workbench.isPanelOpen(activeTabId) && workbench.getMode(activeTabId) === 'browser') {
-                workbench.closePanel(activeTabId)
-                return
-              }
-              const browser = useBrowserPanelStore.getState()
-              const existing = browser.bySession[activeTabId]
-              if (existing) {
-                // Re-surface the workbench in browser mode at the last url
-                // without resetting history. (browser.open resets history.)
-                workbench.setMode(activeTabId, 'browser')
-                workbench.openPanel(activeTabId)
-              } else {
-                browser.open(activeTabId, 'http://localhost:5173/')
-              }
-            }}
-            active={isBrowserPanelOpen}
-          />
-        )}
       </div>
 
       {isTauri && (
diff --git a/desktop/src/components/workbench/WorkbenchPanel.test.tsx b/desktop/src/components/workbench/WorkbenchPanel.test.tsx
index d61f02ba..a3695da3 100644
--- a/desktop/src/components/workbench/WorkbenchPanel.test.tsx
+++ b/desktop/src/components/workbench/WorkbenchPanel.test.tsx
@@ -19,11 +19,13 @@ vi.mock('../browser/BrowserSurface', () => ({
 import { WorkbenchPanel } from './WorkbenchPanel'
 import { useWorkspacePanelStore } from '../../stores/workspacePanelStore'
 import { useSettingsStore } from '../../stores/settingsStore'
+import { useBrowserPanelStore } from '../../stores/browserPanelStore'
 
 const SESSION_ID = 'workbench-session'
 
 beforeEach(() => {
   useWorkspacePanelStore.setState(useWorkspacePanelStore.getInitialState(), true)
+  useBrowserPanelStore.setState(useBrowserPanelStore.getInitialState(), true)
   useSettingsStore.setState({ locale: 'en' })
   useWorkspacePanelStore.getState().openPanel(SESSION_ID)
 })
@@ -31,6 +33,7 @@ beforeEach(() => {
 afterEach(() => {
   cleanup()
   useWorkspacePanelStore.setState(useWorkspacePanelStore.getInitialState(), true)
+  useBrowserPanelStore.setState(useBrowserPanelStore.getInitialState(), true)
 })
 
 describe('WorkbenchPanel', () => {
@@ -66,6 +69,13 @@ describe('WorkbenchPanel', () => {
     fireEvent.click(screen.getByRole('tab', { name: 'Browser' }))
 
     expect(useWorkspacePanelStore.getState().getMode(SESSION_ID)).toBe('browser')
+    expect(useBrowserPanelStore.getState().bySession[SESSION_ID]).toMatchObject({
+      isOpen: true,
+      url: '',
+      history: [],
+      historyIndex: -1,
+      loading: false,
+    })
   })
 
   it('switching to the files tab calls setMode("workspace")', () => {
diff --git a/desktop/src/components/workbench/WorkbenchPanel.tsx b/desktop/src/components/workbench/WorkbenchPanel.tsx
index ef6b6d4a..c348ed86 100644
--- a/desktop/src/components/workbench/WorkbenchPanel.tsx
+++ b/desktop/src/components/workbench/WorkbenchPanel.tsx
@@ -4,6 +4,7 @@ import {
   useWorkspacePanelStore,
   type WorkbenchMode,
 } from '../../stores/workspacePanelStore'
+import { useBrowserPanelStore } from '../../stores/browserPanelStore'
 import { WorkspacePanel } from '../workspace/WorkspacePanel'
 import { BrowserSurface } from '../browser/BrowserSurface'
 
@@ -30,6 +31,14 @@ export function WorkbenchPanel({ sessionId }: WorkbenchPanelProps) {
   const mode = useWorkspacePanelStore((state) => state.getMode(sessionId))
   const setMode = useWorkspacePanelStore((state) => state.setMode)
   const closePanel = useWorkspacePanelStore((state) => state.closePanel)
+  const ensureBlankBrowser = useBrowserPanelStore((state) => state.ensureBlank)
+
+  const handleModeSelect = (nextMode: WorkbenchMode) => {
+    if (nextMode === 'browser') {
+      ensureBlankBrowser(sessionId)
+    }
+    setMode(sessionId, nextMode)
+  }
 
   return (
     <div className="flex h-full min-h-0 w-full flex-col bg-[var(--color-surface)]">
@@ -47,7 +56,7 @@ export function WorkbenchPanel({ sessionId }: WorkbenchPanelProps) {
                 type="button"
                 role="tab"
                 aria-selected={isActive}
-                onClick={() => setMode(sessionId, itemMode)}
+                onClick={() => handleModeSelect(itemMode)}
                 className={`inline-flex h-7 items-center gap-1.5 rounded-[6px] px-2.5 text-[12px] font-medium transition-colors focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-[var(--color-brand)]/35 ${
                   isActive
                     ? 'bg-[var(--color-surface-selected)] text-[var(--color-text-primary)] shadow-[inset_0_0_0_1px_var(--color-border-focus)]'
diff --git a/desktop/src/stores/browserPanelStore.test.ts b/desktop/src/stores/browserPanelStore.test.ts
index f82ea943..5354a8b2 100644
--- a/desktop/src/stores/browserPanelStore.test.ts
+++ b/desktop/src/stores/browserPanelStore.test.ts
@@ -20,6 +20,16 @@ describe('browserPanelStore', () => {
     expect(s.canGoBack).toBe(false)
   })
 
+  it('creates a blank browser session without navigating', () => {
+    useBrowserPanelStore.getState().ensureBlank('s1')
+    const s = useBrowserPanelStore.getState().bySession['s1']!
+    expect(s.url).toBe('')
+    expect(s.isOpen).toBe(true)
+    expect(s.history).toEqual([])
+    expect(s.historyIndex).toBe(-1)
+    expect(s.loading).toBe(false)
+  })
+
   it('navigate pushes history and truncates forward entries', () => {
     const st = useBrowserPanelStore.getState()
     st.open('s1', 'http://localhost/a')
@@ -67,6 +77,17 @@ describe('browserPanelStore', () => {
     expect(useBrowserPanelStore.getState().bySession['s1']!.loading).toBe(true)
   })
 
+  it('navigate from a blank session records the first URL as the first history entry', () => {
+    const st = useBrowserPanelStore.getState()
+    st.ensureBlank('s1')
+    st.navigate('s1', 'http://localhost/a')
+    const s = useBrowserPanelStore.getState().bySession['s1']!
+    expect(s.url).toBe('http://localhost/a')
+    expect(s.history).toEqual(['http://localhost/a'])
+    expect(s.historyIndex).toBe(0)
+    expect(s.canGoBack).toBe(false)
+  })
+
   it('setNavigated clears loading and updates url/title without growing history', () => {
     const st = useBrowserPanelStore.getState()
     st.open('s1', 'http://x/a')
diff --git a/desktop/src/stores/browserPanelStore.ts b/desktop/src/stores/browserPanelStore.ts
index f075604e..55a9e014 100644
--- a/desktop/src/stores/browserPanelStore.ts
+++ b/desktop/src/stores/browserPanelStore.ts
@@ -16,6 +16,7 @@ export type BrowserSessionState = {
 type BrowserPanelState = {
   bySession: Record<string, BrowserSessionState>
   open: (sessionId: string, url: string) => void
+  ensureBlank: (sessionId: string) => void
   navigate: (sessionId: string, url: string) => void
   goBack: (sessionId: string) => void
   goForward: (sessionId: string) => void
@@ -26,14 +27,21 @@ type BrowserPanelState = {
   setReady: (sessionId: string) => void
 }
 
-const empty = (url: string): BrowserSessionState => ({
-  isOpen: true, url, title: '', history: [url], historyIndex: 0,
-  loading: false, pickerActive: false, canGoBack: false, canGoForward: false,
+const empty = (url = ''): BrowserSessionState => ({
+  isOpen: true,
+  url,
+  title: '',
+  history: url ? [url] : [],
+  historyIndex: url ? 0 : -1,
+  loading: false,
+  pickerActive: false,
+  canGoBack: false,
+  canGoForward: false,
 })
 
 const withNav = (s: BrowserSessionState): BrowserSessionState => ({
   ...s,
-  url: s.history[s.historyIndex]!,
+  url: s.history[s.historyIndex] ?? s.url,
   canGoBack: s.historyIndex > 0,
   canGoForward: s.historyIndex < s.history.length - 1,
 })
@@ -51,9 +59,16 @@ export const useBrowserPanelStore = create<BrowserPanelState>((set) => ({
     workspacePanel.openPanel(sessionId)
     workspacePanel.setMode(sessionId, 'browser')
   },
+  ensureBlank: (sessionId) => set((st) => {
+    const cur = st.bySession[sessionId]
+    if (cur) {
+      return { bySession: { ...st.bySession, [sessionId]: { ...cur, isOpen: true } } }
+    }
+    return { bySession: { ...st.bySession, [sessionId]: empty() } }
+  }),
   navigate: (sessionId, url) => set((st) => {
     const cur = st.bySession[sessionId] ?? empty(url)
-    const history = [...cur.history.slice(0, cur.historyIndex + 1), url]
+    const history = [...cur.history.slice(0, Math.max(0, cur.historyIndex + 1)), url]
     return { bySession: { ...st.bySession, [sessionId]: withNav({ ...cur, isOpen: true, loading: true, history, historyIndex: history.length - 1 }) } }
   }),
   goBack: (sessionId) => set((st) => {