diff --git a/server/session-scanner/service.ts b/server/session-scanner/service.ts
index 38af37e2..c7f21bc8 100644
--- a/server/session-scanner/service.ts
+++ b/server/session-scanner/service.ts
@@ -167,6 +167,21 @@ export class SessionRepairService extends EventEmitter {
     }
 
     if (this.queue.has(sessionId)) {
+      // Check disk cache before waiting for queue processing.
+      // Sessions discovered at startup are enqueued before cache is consulted,
+      // so this avoids blocking on the queue when the cache has a valid result.
+      const cachedPath = this.resolveCachedPath(sessionId)
+      if (cachedPath) {
+        const cached = await this.cache.get(cachedPath, { allowStaleMs: ACTIVE_CACHE_GRACE_MS })
+        if (cached) {
+          const normalized = cached.sessionId === sessionId
+            ? cached
+            : { ...cached, sessionId }
+          this.queue.seedResult(sessionId, normalized)
+          await this.ensureSessionArtifacts(normalized)
+          return normalized
+        }
+      }
       return this.queue.waitFor(sessionId, timeoutMs)
     }
 
diff --git a/server/ws-handler.ts b/server/ws-handler.ts
index d5c4037c..7531c096 100644
--- a/server/ws-handler.ts
+++ b/server/ws-handler.ts
@@ -309,7 +309,7 @@ export class WsHandler {
   private screenshotRequests = new Map<string, PendingScreenshot>()
   private sessionsRevision = 0
   private terminalsRevision = 0
-  private terminalRuntimeRevisions = new Map<string, number>()
+
   private readonly serverInstanceId: string
   private readonly bootId: string
   // The runtime validator is authoritative here; we keep the field typed broadly because
@@ -1435,7 +1435,6 @@ export class WsHandler {
         }
         if (attachResult === 'duplicate') return
         state.attachedTerminalIds.add(m.terminalId)
-        this.broadcastTerminalRuntimeUpdatedForId(m.terminalId)
         return
       }
 
@@ -1447,7 +1446,6 @@ export class WsHandler {
           return
         }
         this.send(ws, { type: 'terminal.detached', terminalId: m.terminalId })
-        this.broadcastTerminalRuntimeUpdatedForId(m.terminalId)
         return
       }
 
@@ -1474,7 +1472,6 @@ export class WsHandler {
           return
         }
         this.broadcastTerminalsChanged()
-        this.broadcastTerminalRuntimeUpdatedForId(m.terminalId)
         return
       }
 
@@ -2037,59 +2034,6 @@ export class WsHandler {
     })
   }
 
-  private resolveTerminalRuntimePayload(terminalId: string): {
-    terminalId: string
-    title: string
-    status: 'running' | 'detached' | 'exited'
-    cwd?: string
-    pid?: number
-  } | null {
-    const record = this.registry.get(terminalId) as
-      | {
-          terminalId: string
-          title: string
-          status: 'running' | 'exited'
-          cwd?: string
-          pty?: { pid?: number }
-          clients?: Set<unknown>
-        }
-      | null
-      | undefined
-
-    if (!record) return null
-
-    return {
-      terminalId: record.terminalId,
-      title: record.title,
-      status: record.status === 'exited'
-        ? 'exited'
-        : ((record.clients?.size ?? 0) > 0 ? 'running' : 'detached'),
-      ...(record.cwd ? { cwd: record.cwd } : {}),
-      ...(typeof record.pty?.pid === 'number' ? { pid: record.pty.pid } : {}),
-    }
-  }
-
-  broadcastTerminalRuntimeUpdated(msg: {
-    terminalId: string
-    title: string
-    status: 'running' | 'detached' | 'exited'
-    cwd?: string
-    pid?: number
-  }): void {
-    const revision = (this.terminalRuntimeRevisions.get(msg.terminalId) ?? 0) + 1
-    this.terminalRuntimeRevisions.set(msg.terminalId, revision)
-    this.broadcastAuthenticated({
-      type: 'terminal.runtime.updated',
-      revision,
-      ...msg,
-    })
-  }
-
-  private broadcastTerminalRuntimeUpdatedForId(terminalId: string): void {
-    const payload = this.resolveTerminalRuntimePayload(terminalId)
-    if (!payload) return
-    this.broadcastTerminalRuntimeUpdated(payload)
-  }
 
   broadcastTerminalMetaUpdated(msg: { upsert?: TerminalMeta[]; remove?: string[] }): void {
     const parsed = TerminalMetaUpdatedSchema.safeParse({
diff --git a/shared/ws-protocol.ts b/shared/ws-protocol.ts
index fb0190b8..69078dd3 100644
--- a/shared/ws-protocol.ts
+++ b/shared/ws-protocol.ts
@@ -484,16 +484,6 @@ export type TerminalsChangedMessage = {
   revision: number
 }
 
-export type TerminalRuntimeUpdatedMessage = {
-  type: 'terminal.runtime.updated'
-  terminalId: string
-  revision: number
-  status: 'running' | 'detached' | 'exited'
-  title: string
-  cwd?: string
-  pid?: number
-}
-
 export type TerminalMetaUpdatedMessage = z.infer<typeof TerminalMetaUpdatedSchema>
 
 export type CodexActivityListResponseMessage = z.infer<typeof CodexActivityListResponseSchema>
@@ -697,7 +687,6 @@ export type ServerMessage =
   | TerminalTitleUpdatedMessage
   | TerminalSessionAssociatedMessage
   | TerminalsChangedMessage
-  | TerminalRuntimeUpdatedMessage
   | TerminalMetaUpdatedMessage
   | TerminalInventoryMessage
   | CodexActivityListResponseMessage
diff --git a/src/components/BackgroundSessions.tsx b/src/components/BackgroundSessions.tsx
index c0732be8..657c75bd 100644
--- a/src/components/BackgroundSessions.tsx
+++ b/src/components/BackgroundSessions.tsx
@@ -1,9 +1,11 @@
 import { useCallback, useEffect, useMemo } from 'react'
+import { nanoid } from 'nanoid'
 import { getWsClient } from '@/lib/ws-client'
 import { Button } from '@/components/ui/button'
 import { Badge } from '@/components/ui/badge'
 import { useAppDispatch, useAppSelector } from '@/store/hooks'
 import { addTab } from '@/store/tabsSlice'
+import { initLayout } from '@/store/panesSlice'
 import { fetchTerminalDirectoryWindow } from '@/store/terminalDirectoryThunks'
 
 type BackgroundTerminal = {
@@ -97,7 +99,10 @@ export default function BackgroundSessions() {
                     size="sm"
                     variant="outline"
                     onClick={() => {
-                      dispatch(addTab({ title: t.title, terminalId: t.terminalId, status: 'running', mode: (t.mode as any) || 'shell', resumeSessionId: t.resumeSessionId }))
+                      const tabId = nanoid()
+                      const mode = ((t.mode as any) || 'shell') as string
+                      dispatch(addTab({ id: tabId, title: t.title, status: 'running', mode: mode as any, resumeSessionId: t.resumeSessionId }))
+                      dispatch(initLayout({ tabId, content: { kind: 'terminal', mode: mode as any, terminalId: t.terminalId, status: 'running', resumeSessionId: t.resumeSessionId } }))
                     }}
                   >
                     Attach
diff --git a/src/components/OverviewView.tsx b/src/components/OverviewView.tsx
index 4f06400b..00ab071b 100644
--- a/src/components/OverviewView.tsx
+++ b/src/components/OverviewView.tsx
@@ -1,8 +1,11 @@
-import { useEffect, useMemo, useState } from 'react'
+import { useCallback, useEffect, useMemo, useState } from 'react'
+import { nanoid } from 'nanoid'
 import { api } from '@/lib/api'
 import { useAppDispatch, useAppSelector } from '@/store/hooks'
 import { addTab, setActiveTab, updateTab } from '@/store/tabsSlice'
+import { initLayout } from '@/store/panesSlice'
 import { getWsClient } from '@/lib/ws-client'
+import { collectTerminalIds } from '@/lib/pane-utils'
 import { cn } from '@/lib/utils'
 import { RefreshCw, Circle, Play, Pencil, Trash2, Sparkles, ExternalLink } from 'lucide-react'
 import { ContextIds } from '@/components/context-menu/context-menu-constants'
@@ -44,9 +47,20 @@ function formatDuration(ms: number): string {
 export default function OverviewView({ onOpenTab }: { onOpenTab?: () => void }) {
   const dispatch = useAppDispatch()
   const tabs = useAppSelector((s) => s.tabs.tabs)
+  const paneLayouts = useAppSelector((s) => s.panes.layouts)
 
   const ws = useMemo(() => getWsClient(), [])
 
+  const findTabByTerminalId = useCallback((terminalId: string) => {
+    for (const tab of tabs) {
+      const layout = paneLayouts[tab.id]
+      if (layout && collectTerminalIds(layout).includes(terminalId)) {
+        return tab
+      }
+    }
+    return undefined
+  }, [tabs, paneLayouts])
+
   const [items, setItems] = useState<TerminalOverview[]>([])
   const [loading, setLoading] = useState(false)
   const [error, setError] = useState<string | null>(null)
@@ -137,15 +151,17 @@ export default function OverviewView({ onOpenTab }: { onOpenTab?: () => void })
                     <TerminalCard
                       key={t.terminalId}
                       terminal={t}
-                      isOpen={tabs.some((x) => x.terminalId === t.terminalId)}
+                      isOpen={!!findTabByTerminalId(t.terminalId)}
                       onOpen={() => {
-                        const existing = tabs.find((x) => x.terminalId === t.terminalId)
+                        const existing = findTabByTerminalId(t.terminalId)
                         if (existing) {
                           dispatch(setActiveTab(existing.id))
                           onOpenTab?.()
                           return
                         }
-                        dispatch(addTab({ title: t.title, terminalId: t.terminalId, status: 'running', mode: 'shell' }))
+                        const tabId = nanoid()
+                        dispatch(addTab({ id: tabId, title: t.title, status: 'running', mode: 'shell' }))
+                        dispatch(initLayout({ tabId, content: { kind: 'terminal', mode: 'shell', terminalId: t.terminalId, status: 'running' } }))
                         onOpenTab?.()
                       }}
                       onRename={async (title, description) => {
@@ -153,7 +169,7 @@ export default function OverviewView({ onOpenTab }: { onOpenTab?: () => void })
                           titleOverride: title || undefined,
                           descriptionOverride: description || undefined,
                         })
-                        const existing = tabs.find((x) => x.terminalId === t.terminalId)
+                        const existing = findTabByTerminalId(t.terminalId)
                         if (existing && title) {
                           dispatch(updateTab({ id: existing.id, updates: { title } }))
                         }
@@ -192,15 +208,17 @@ export default function OverviewView({ onOpenTab }: { onOpenTab?: () => void })
                     <TerminalCard
                       key={t.terminalId}
                       terminal={t}
-                      isOpen={tabs.some((x) => x.terminalId === t.terminalId)}
+                      isOpen={!!findTabByTerminalId(t.terminalId)}
                       onOpen={() => {
-                        const existing = tabs.find((x) => x.terminalId === t.terminalId)
+                        const existing = findTabByTerminalId(t.terminalId)
                         if (existing) {
                           dispatch(setActiveTab(existing.id))
                           onOpenTab?.()
                           return
                         }
-                        dispatch(addTab({ title: t.title, terminalId: t.terminalId, status: 'exited', mode: 'shell' }))
+                        const tabId = nanoid()
+                        dispatch(addTab({ id: tabId, title: t.title, status: 'exited', mode: 'shell' }))
+                        dispatch(initLayout({ tabId, content: { kind: 'terminal', mode: 'shell', terminalId: t.terminalId, status: 'exited' } }))
                         onOpenTab?.()
                       }}
                       onRename={async (title, description) => {
diff --git a/src/components/Sidebar.tsx b/src/components/Sidebar.tsx
index 577a0756..cd498b9c 100644
--- a/src/components/Sidebar.tsx
+++ b/src/components/Sidebar.tsx
@@ -19,6 +19,7 @@ import { getInstalledPerfAuditBridge } from '@/lib/perf-audit-bridge'
 import { fetchSessionWindow } from '@/store/sessionsThunks'
 import { mergeSessionMetadataByKey } from '@/lib/session-metadata'
 import { collectBusySessionKeys } from '@/lib/pane-activity'
+import { selectPrimaryTerminalIdForTab } from '@/store/selectors/paneTerminalSelectors'
 import type { ChatSessionState } from '@/store/agentChatTypes'
 import type { PaneRuntimeActivityRecord } from '@/store/paneRuntimeActivitySlice'
 
@@ -388,7 +389,6 @@ export default function Sidebar({
         sessionType,
         sessionId: item.sessionId,
         cwd: item.cwd,
-        terminalId: runningTerminalId,
         agentChatProviderSettings: providerSettings,
       }),
     }))
@@ -421,9 +421,8 @@ export default function Sidebar({
     { id: 'settings' as const, label: 'Settings', icon: Settings, shortcut: ',' },
   ]
 
-  const activeTab = tabs.find((t) => t.id === activeTabId)
   const activeSessionKey = activeSessionKeyFromPanes
-  const activeTerminalId = activeTab?.terminalId
+  const activeTerminalId = useAppSelector((s) => activeTabId ? selectPrimaryTerminalIdForTab(s, activeTabId) : undefined)
   const hasLoadedSidebarWindow = typeof sidebarWindow?.lastLoadedAt === 'number'
   const sidebarWindowHasItems = (sidebarWindow?.projects ?? []).some((project) => (project.sessions?.length ?? 0) > 0)
   const visibleQuery = appliedQuery || requestedQuery
diff --git a/src/components/TabBar.tsx b/src/components/TabBar.tsx
index 63e54458..a90ac573 100644
--- a/src/components/TabBar.tsx
+++ b/src/components/TabBar.tsx
@@ -185,7 +185,6 @@ export default function TabBar({ sidebarCollapsed, onToggleSidebar }: TabBarProp
           shell: tab.shell,
           createRequestId: tab.createRequestId,
           status: tab.status,
-          terminalId: tab.terminalId,
           resumeSessionId: tab.resumeSessionId,
           initialCwd: tab.initialCwd,
         },
@@ -202,7 +201,7 @@ export default function TabBar({ sidebarCollapsed, onToggleSidebar }: TabBarProp
         return Array.from(new Set(ids))
       }
     }
-    return tab.terminalId ? [tab.terminalId] : []
+    return []
   }, [paneLayouts])
 
   const getBusyPaneIds = useCallback((tab: Tab): string[] => getBusyPaneIdsForTab({
diff --git a/src/components/TabContent.tsx b/src/components/TabContent.tsx
index fd941817..4ea91e1b 100644
--- a/src/components/TabContent.tsx
+++ b/src/components/TabContent.tsx
@@ -15,6 +15,7 @@ interface TabContentProps {
 
 export default function TabContent({ tabId, hidden }: TabContentProps) {
   const tab = useAppSelector((s) => s.tabs.tabs.find((t) => t.id === tabId))
+  const hasLayout = useAppSelector((s) => !!s.panes.layouts[tabId])
   const defaultNewPane = useAppSelector((s) => s.settings.settings.panes?.defaultNewPane || 'ask')
   const previousHiddenRef = useRef(hidden)
 
@@ -27,8 +28,8 @@ export default function TabContent({ tabId, hidden }: TabContentProps) {
 
   if (!tab) return null
 
-  // For coding CLI session views with no terminal, use SessionView
-  if (tab.codingCliSessionId && !tab.terminalId) {
+  // For coding CLI session views with no terminal pane, use SessionView
+  if (tab.codingCliSessionId && !hasLayout) {
     return <SessionView sessionId={tab.codingCliSessionId} hidden={hidden} />
   }
 
@@ -36,16 +37,7 @@ export default function TabContent({ tabId, hidden }: TabContentProps) {
   let defaultContent: PaneContentInput
   const resumeSessionType = getTabResumeSessionType(tab)
 
-  if (tab.terminalId) {
-    defaultContent = {
-      kind: 'terminal',
-      mode: tab.mode,
-      shell: tab.shell,
-      resumeSessionId: tab.resumeSessionId,
-      initialCwd: tab.initialCwd,
-      terminalId: tab.terminalId,
-    }
-  } else if (tab.resumeSessionId && resumeSessionType) {
+  if (tab.resumeSessionId && resumeSessionType) {
     defaultContent = buildResumeContent({
       sessionType: resumeSessionType,
       sessionId: tab.resumeSessionId,
@@ -58,7 +50,6 @@ export default function TabContent({ tabId, hidden }: TabContentProps) {
       shell: tab.shell,
       resumeSessionId: tab.resumeSessionId,
       initialCwd: tab.initialCwd,
-      terminalId: tab.terminalId,
     }
   } else if (defaultNewPane === 'ask') {
     defaultContent = { kind: 'picker' }
@@ -81,7 +72,6 @@ export default function TabContent({ tabId, hidden }: TabContentProps) {
       shell: tab.shell,
       resumeSessionId: tab.resumeSessionId,
       initialCwd: tab.initialCwd,
-      terminalId: tab.terminalId,
     }
   }
 
diff --git a/src/components/TerminalView.tsx b/src/components/TerminalView.tsx
index 03e22da6..914bfd04 100644
--- a/src/components/TerminalView.tsx
+++ b/src/components/TerminalView.tsx
@@ -1783,10 +1783,10 @@ export default function TerminalView({ tabId, paneId, paneContent, hidden }: Ter
           })
           terminalIdRef.current = newId
           updateContent({ terminalId: newId, status: 'running' })
-          // Also update tab for title purposes
+          // Also update tab status
           const currentTab = tabRef.current
           if (currentTab) {
-            dispatch(updateTab({ id: currentTab.id, updates: { terminalId: newId, status: 'running' } }))
+            dispatch(updateTab({ id: currentTab.id, updates: { status: 'running' } }))
           }
           if (msg.effectiveResumeSessionId && msg.effectiveResumeSessionId !== contentRef.current?.resumeSessionId) {
             updateContent({ resumeSessionId: msg.effectiveResumeSessionId })
@@ -1828,7 +1828,7 @@ export default function TerminalView({ tabId, paneId, paneContent, hidden }: Ter
           if (exitTab) {
             const code = typeof msg.exitCode === 'number' ? msg.exitCode : undefined
             // Only modify title if user hasn't manually set it
-            const updates: { terminalId: undefined; status: 'exited'; title?: string } = { terminalId: undefined, status: 'exited' }
+            const updates: { status: 'exited'; title?: string } = { status: 'exited' }
             if (!exitTab.titleSetByUser) {
               updates.title = exitTab.title + (code !== undefined ? ` (exit ${code})` : '')
             }
@@ -1940,11 +1940,9 @@ export default function TerminalView({ tabId, paneId, paneContent, hidden }: Ter
             }
             applySeqState(createAttachSeqState())
             updateContent({ terminalId: undefined, createRequestId: newRequestId, status: 'creating' })
-            // Also clear the tab's terminalId to keep it in sync.
-            // This prevents openSessionTab from using the stale terminalId for dedup.
             const currentTab = tabRef.current
             if (currentTab) {
-              dispatch(updateTab({ id: currentTab.id, updates: { terminalId: undefined, status: 'creating' } }))
+              dispatch(updateTab({ id: currentTab.id, updates: { status: 'creating' } }))
             }
           } else if (current?.status === 'exited') {
             term.writeln('\r\n[Terminal exited - use the + button or split to start a new session]\r\n')
diff --git a/src/components/context-menu/ContextMenuProvider.tsx b/src/components/context-menu/ContextMenuProvider.tsx
index e809baa9..447cf49b 100644
--- a/src/components/context-menu/ContextMenuProvider.tsx
+++ b/src/components/context-menu/ContextMenuProvider.tsx
@@ -237,22 +237,14 @@ export function ContextMenuProvider({
     dispatch(requestTabRefresh({ tabId }))
   }, [dispatch])
 
-  const clearStaleTabTerminalId = useCallback((tabId: string, detachedTerminalId: string) => {
-    const tab = tabsState.tabs.find((t) => t.id === tabId)
-    if (tab?.terminalId === detachedTerminalId) {
-      dispatch(updateTab({ id: tabId, updates: { terminalId: undefined } }))
-    }
-  }, [dispatch, tabsState.tabs])
-
   const replacePaneAction = useCallback((tabId: string, paneId: string) => {
     if (!panes[tabId]) return
     const content = findPaneContent(panes[tabId], paneId)
     if (content?.kind === 'terminal' && content.terminalId) {
       ws.send({ type: 'terminal.detach', terminalId: content.terminalId })
-      clearStaleTabTerminalId(tabId, content.terminalId)
     }
     dispatch(replacePane({ tabId, paneId }))
-  }, [dispatch, panes, ws, clearStaleTabTerminalId])
+  }, [dispatch, panes, ws])
 
   const closeTabById = useCallback((tabId: string) => {
     const layout = panes[tabId]
@@ -414,7 +406,6 @@ export function ContextMenuProvider({
         sessionType,
         sessionId: session.sessionId,
         cwd: session.cwd,
-        terminalId: runningTerminalId || undefined,
         agentChatProviderSettings: providerSettings,
       }),
     }))
@@ -619,14 +610,29 @@ export function ContextMenuProvider({
     await copyText(projectPath)
   }, [])
 
+  const findTabByTerminalId = useCallback((terminalId: string) => {
+    for (const tab of tabsState.tabs) {
+      const layout = panes[tab.id]
+      if (layout && collectTerminalIds(layout).includes(terminalId)) {
+        return tab
+      }
+    }
+    return undefined
+  }, [tabsState.tabs, panes])
+
   const openTerminal = useCallback((terminalId: string) => {
-    const existing = tabsState.tabs.find((t) => t.terminalId === terminalId)
+    const existing = findTabByTerminalId(terminalId)
     if (existing) {
       dispatch(setActiveTab(existing.id))
       return
     }
-    dispatch(addTab({ terminalId, status: 'running', mode: 'shell' }))
-  }, [dispatch, tabsState.tabs])
+    const tabId = nanoid()
+    dispatch(addTab({ id: tabId, status: 'running', mode: 'shell' }))
+    dispatch(initLayout({
+      tabId,
+      content: { kind: 'terminal', mode: 'shell', terminalId, status: 'running' },
+    }))
+  }, [dispatch, findTabByTerminalId])
 
   const renameTerminal = useCallback(async (terminalId: string) => {
     let currentTitle = ''
@@ -650,14 +656,14 @@ export function ContextMenuProvider({
         titleOverride: title || undefined,
         descriptionOverride: description || undefined,
       })
-      const existing = tabsState.tabs.find((t) => t.terminalId === terminalId)
+      const existing = findTabByTerminalId(terminalId)
       if (existing && title) {
         dispatch(updateTab({ id: existing.id, updates: { title } }))
       }
     } catch {
       // ignore
     }
-  }, [dispatch, tabsState.tabs])
+  }, [dispatch, findTabByTerminalId])
 
   const generateTerminalSummary = useCallback(async (terminalId: string) => {
     try {
@@ -948,7 +954,6 @@ export function ContextMenuProvider({
           const content = panes[tabId] ? findPaneContent(panes[tabId], paneId) : null
           if (content?.kind === 'terminal' && content.terminalId) {
             ws.send({ type: 'terminal.detach', terminalId: content.terminalId })
-            clearStaleTabTerminalId(tabId, content.terminalId)
           }
           dispatch(closePaneWithCleanup({ tabId, paneId }))
         },
@@ -1019,7 +1024,6 @@ export function ContextMenuProvider({
     renamePane,
     refreshPaneAction,
     replacePaneAction,
-    clearStaleTabTerminalId,
     ws,
     dispatch,
     openSessionInNewTab,
diff --git a/src/components/panes/PaneContainer.tsx b/src/components/panes/PaneContainer.tsx
index 698e3040..1f5e34ea 100644
--- a/src/components/panes/PaneContainer.tsx
+++ b/src/components/panes/PaneContainer.tsx
@@ -1,7 +1,7 @@
 import { useRef, useCallback, useMemo, useState, useEffect } from 'react'
 import { useAppDispatch, useAppSelector } from '@/store/hooks'
 import { setActivePane, resizePanes, updatePaneContent, clearPaneRenameRequest, toggleZoom, requestPaneRefresh } from '@/store/panesSlice'
-import { updateTab, closePaneWithCleanup } from '@/store/tabsSlice'
+import { closePaneWithCleanup } from '@/store/tabsSlice'
 import type { PaneNode, PaneContent } from '@/store/paneTypes'
 import Pane from './Pane'
 import PaneDivider from './PaneDivider'
@@ -71,7 +71,6 @@ function resolvePaneRuntimeMeta(
   terminalMetaById: Record<string, TerminalMetaRecord>,
   options: {
     terminalId?: string
-    tabTerminalId?: string
     isOnlyPane: boolean
     provider?: CodingCliProviderName
     resumeSessionId?: string
@@ -83,13 +82,6 @@ function resolvePaneRuntimeMeta(
     if (byTerminalId) return byTerminalId
   }
 
-  // During refresh/rehydration, single-pane tabs can briefly have tab-level
-  // terminal IDs before the pane content is fully reattached.
-  if (!options.terminalId && options.isOnlyPane && options.tabTerminalId) {
-    const byTabTerminalId = terminalMetaById[options.tabTerminalId]
-    if (byTabTerminalId) return byTabTerminalId
-  }
-
   if (options.resumeSessionId && options.provider) {
     return Object.values(terminalMetaById).find((record) => (
       record.provider === options.provider && record.sessionId === options.resumeSessionId
@@ -162,7 +154,6 @@ export default function PaneContainer({ tabId, node, hidden }: PaneContainerProp
   const dispatch = useAppDispatch()
   const activePane = useAppSelector((s) => s.panes.activePane[tabId])
   const tab = useAppSelector((s) => s.tabs.tabs.find((t) => t.id === tabId))
-  const tabTerminalId = tab?.terminalId
   const paneTitles = useAppSelector((s) => s.panes.paneTitles[tabId] ?? EMPTY_PANE_TITLES)
   const extensionEntries = useAppSelector((s) => s.extensions?.entries ?? EMPTY_EXTENSION_ENTRIES)
   const terminalMetaById = useAppSelector(
@@ -277,11 +268,6 @@ export default function PaneContainer({ tabId, node, hidden }: PaneContainerProp
         type: 'terminal.detach',
         terminalId: content.terminalId,
       })
-      // Clear stale tab.terminalId so background-terminal dedup doesn't
-      // focus this tab after the pane's terminal has been detached
-      if (tabTerminalId === content.terminalId) {
-        dispatch(updateTab({ id: tabId, updates: { terminalId: undefined } }))
-      }
     }
     // Clean up agent-chat resources
     if (content.kind === 'agent-chat') {
@@ -305,7 +291,7 @@ export default function PaneContainer({ tabId, node, hidden }: PaneContainerProp
     // Extension panes: V1 leaves server extensions running until freshell shutdown.
     // Future: stop singleton server when its last pane closes.
     dispatch(closePaneWithCleanup({ tabId, paneId }))
-  }, [dispatch, tabId, tabTerminalId, ws, sdkPendingCreates])
+  }, [dispatch, tabId, ws, sdkPendingCreates])
 
   const handleFocus = useCallback((paneId: string) => {
     if (attentionDismiss === 'click' && attentionByPane[paneId]) {
@@ -407,7 +393,6 @@ export default function PaneContainer({ tabId, node, hidden }: PaneContainerProp
       node.content.kind === 'terminal'
         ? resolvePaneRuntimeMeta(terminalMetaById, {
           terminalId: node.content.terminalId,
-          tabTerminalId,
           isOnlyPane,
           provider: paneProvider,
           resumeSessionId: paneResumeSessionId,
@@ -432,7 +417,6 @@ export default function PaneContainer({ tabId, node, hidden }: PaneContainerProp
       paneId: node.id,
       content: node.content,
       tabMode: tab?.mode,
-      tabTerminalId,
       isOnlyPane,
       codexActivityByTerminalId,
       paneRuntimeActivityByPaneId,
diff --git a/src/lib/codex-activity-resolver.ts b/src/lib/codex-activity-resolver.ts
index 67389743..03aa9ca4 100644
--- a/src/lib/codex-activity-resolver.ts
+++ b/src/lib/codex-activity-resolver.ts
@@ -2,9 +2,8 @@ import type { CodexActivityRecord } from '@shared/ws-protocol'
 
 export function resolveExactCodexActivity(
   byTerminalId: Record<string, CodexActivityRecord>,
-  opts: { terminalId?: string; tabTerminalId?: string; isOnlyPane: boolean },
+  opts: { terminalId?: string; isOnlyPane: boolean },
 ): CodexActivityRecord | undefined {
   if (opts.terminalId) return byTerminalId[opts.terminalId]
-  if (opts.isOnlyPane && opts.tabTerminalId) return byTerminalId[opts.tabTerminalId]
   return undefined
 }
diff --git a/src/lib/pane-activity.ts b/src/lib/pane-activity.ts
index ba71a9e1..d6fbc911 100644
--- a/src/lib/pane-activity.ts
+++ b/src/lib/pane-activity.ts
@@ -94,7 +94,6 @@ function buildSyntheticTerminalContent(tab: Tab): TerminalPaneContent | null {
     status: tab.status,
     mode: tab.mode,
     shell: tab.shell,
-    terminalId: tab.terminalId,
     resumeSessionId: tab.resumeSessionId,
     initialCwd: tab.initialCwd,
   }
@@ -104,7 +103,6 @@ export function resolvePaneActivity(input: {
   paneId: string
   content: PaneContent
   tabMode?: Tab['mode']
-  tabTerminalId?: string
   isOnlyPane: boolean
   codexActivityByTerminalId: Record<string, CodexActivityRecord>
   paneRuntimeActivityByPaneId: Record<string, PaneRuntimeActivityRecord>
@@ -122,7 +120,6 @@ export function resolvePaneActivity(input: {
     if (effectiveMode === 'codex') {
       const record = resolveExactCodexActivity(input.codexActivityByTerminalId, {
         terminalId: input.content.terminalId,
-        tabTerminalId: input.tabTerminalId,
         isOnlyPane: input.isOnlyPane,
       })
       return record?.phase === 'busy'
@@ -171,7 +168,6 @@ export function getBusyPaneIdsForTab(input: {
       paneId: input.tab.id,
       content: syntheticContent,
       tabMode: input.tab.mode,
-      tabTerminalId: input.tab.terminalId,
       isOnlyPane: true,
       codexActivityByTerminalId: input.codexActivityByTerminalId,
       paneRuntimeActivityByPaneId: input.paneRuntimeActivityByPaneId,
@@ -187,7 +183,6 @@ export function getBusyPaneIdsForTab(input: {
       paneId: entry.paneId,
       content: entry.content,
       tabMode: input.tab.mode,
-      tabTerminalId: input.tab.terminalId,
       isOnlyPane,
       codexActivityByTerminalId: input.codexActivityByTerminalId,
       paneRuntimeActivityByPaneId: input.paneRuntimeActivityByPaneId,
@@ -215,7 +210,6 @@ export function collectBusySessionKeys(input: {
         paneId: tab.id,
         content: syntheticContent,
         tabMode: tab.mode,
-        tabTerminalId: tab.terminalId,
         isOnlyPane: true,
         codexActivityByTerminalId: input.codexActivityByTerminalId,
         paneRuntimeActivityByPaneId: input.paneRuntimeActivityByPaneId,
@@ -234,7 +228,6 @@ export function collectBusySessionKeys(input: {
         paneId: entry.paneId,
         content: entry.content,
         tabMode: tab.mode,
-        tabTerminalId: tab.terminalId,
         isOnlyPane,
         codexActivityByTerminalId: input.codexActivityByTerminalId,
         paneRuntimeActivityByPaneId: input.paneRuntimeActivityByPaneId,
diff --git a/src/lib/session-type-utils.ts b/src/lib/session-type-utils.ts
index 2a67b181..9b5dc931 100644
--- a/src/lib/session-type-utils.ts
+++ b/src/lib/session-type-utils.ts
@@ -46,7 +46,6 @@ export function buildResumeContent(opts: {
   sessionType: string
   sessionId: string
   cwd?: string
-  terminalId?: string
   agentChatProviderSettings?: {
     defaultModel?: string
     defaultPermissionMode?: string
@@ -75,7 +74,5 @@ export function buildResumeContent(opts: {
     mode: provider,
     resumeSessionId: opts.sessionId,
     initialCwd: opts.cwd,
-    terminalId: opts.terminalId,
-    status: opts.terminalId ? 'running' as const : 'creating' as const,
   }
 }
diff --git a/src/lib/tab-codex-activity.ts b/src/lib/tab-codex-activity.ts
index 39dfb482..8ecfd7cd 100644
--- a/src/lib/tab-codex-activity.ts
+++ b/src/lib/tab-codex-activity.ts
@@ -13,13 +13,6 @@ export function getBusyCodexActivityTerminalIdsForTab(
 ): string[] {
   const layout = paneLayouts[tab.id]
   if (!layout) {
-    if (
-      tab.terminalId
-      && tab.status === 'running'
-      && codexActivityByTerminalId[tab.terminalId]?.phase === 'busy'
-    ) {
-      return [tab.terminalId]
-    }
     return EMPTY_ACTIVITY_TERMINAL_IDS
   }
 
@@ -30,7 +23,6 @@ export function getBusyCodexActivityTerminalIdsForTab(
     if (content.status !== 'running') continue
     const record = resolveExactCodexActivity(codexActivityByTerminalId, {
       terminalId: content.terminalId,
-      tabTerminalId: tab.terminalId,
       isOnlyPane,
     })
     if (record?.phase === 'busy') {
diff --git a/src/lib/ui-commands.ts b/src/lib/ui-commands.ts
index c0c17932..b6735250 100644
--- a/src/lib/ui-commands.ts
+++ b/src/lib/ui-commands.ts
@@ -82,7 +82,6 @@ export function handleUiCommand(msg: any, runtimeOrDispatch: UiCommandRuntime |
         title: msg.payload.title,
         mode: msg.payload.mode,
         shell: msg.payload.shell,
-        terminalId: msg.payload.terminalId,
         initialCwd: msg.payload.initialCwd,
         resumeSessionId: msg.payload.resumeSessionId,
         status: msg.payload.status,
@@ -90,6 +89,20 @@ export function handleUiCommand(msg: any, runtimeOrDispatch: UiCommandRuntime |
       if (msg.payload.paneId && msg.payload.paneContent) {
         return dispatch(initLayout({ tabId: msg.payload.id, paneId: msg.payload.paneId, content: msg.payload.paneContent }))
       }
+      if (msg.payload.terminalId) {
+        return dispatch(initLayout({
+          tabId: msg.payload.id,
+          content: {
+            kind: 'terminal',
+            mode: msg.payload.mode || 'shell',
+            terminalId: msg.payload.terminalId,
+            status: msg.payload.status || 'running',
+            shell: msg.payload.shell,
+            initialCwd: msg.payload.initialCwd,
+            resumeSessionId: msg.payload.resumeSessionId,
+          },
+        }))
+      }
       return
     case 'tab.select':
       return dispatch(setActiveTab(msg.payload.id))
diff --git a/src/store/crossTabSync.ts b/src/store/crossTabSync.ts
index 31a0d2a5..4a3c56d7 100644
--- a/src/store/crossTabSync.ts
+++ b/src/store/crossTabSync.ts
@@ -5,7 +5,7 @@ import { setLocalSettings } from './settingsSlice'
 import { setTabRegistrySearchRangeDays } from './tabRegistrySlice'
 import { hydrateTabs } from './tabsSlice'
 import { getPendingBrowserPreferencesWriteState } from './browserPreferencesPersistence'
-import { parsePersistedPanesRaw, parsePersistedTabsRaw, PANES_STORAGE_KEY, TABS_STORAGE_KEY } from './persistedState'
+import { parsePersistedLayoutRaw, LAYOUT_STORAGE_KEY } from './persistedState'
 import { getPersistBroadcastSourceId, onPersistBroadcast, PERSIST_BROADCAST_CHANNEL_NAME } from './persistBroadcast'
 import { BROWSER_PREFERENCES_STORAGE_KEY } from './storage-keys'
 import { parseBrowserPreferencesRaw, resolveBrowserPreferenceSettings } from '@/lib/browser-preferences'
@@ -46,42 +46,27 @@ function collectPaneIdsSafe(node: unknown): string[] {
   return ids
 }
 
-function dispatchHydrateTabsFromPersisted(store: StoreLike, raw: string) {
-  const parsed = parsePersistedTabsRaw(raw)
+function dispatchHydrateLayoutFromPersisted(store: StoreLike, raw: string) {
+  const parsed = parsePersistedLayoutRaw(raw)
   if (!parsed) return
 
-  const remoteTabs = parsed.tabs.tabs
-  const remoteIds = new Set(remoteTabs.map((t: any) => t?.id).filter((id: any): id is string => typeof id === 'string'))
-
-  const state = store.getState()
-  const localActive = state?.tabs?.activeTabId as string | null | undefined
-
-  const desired = (localActive && remoteIds.has(localActive)) ? localActive : parsed.tabs.activeTabId
-  const activeTabId =
-    desired && remoteIds.has(desired)
-      ? desired
-      : (remoteTabs[0]?.id ?? null)
-
+  // Hydrate tabs with merge
   store.dispatch({
     ...hydrateTabs({
-      tabs: remoteTabs,
-      activeTabId,
+      tabs: parsed.tabs.tabs,
+      activeTabId: parsed.tabs.activeTabId,
       renameRequestTabId: null,
+      tombstones: parsed.tombstones,
     } as any),
     meta: { skipPersist: true, source: 'cross-tab' },
   })
-}
-
-function dispatchHydratePanesFromPersisted(store: StoreLike, raw: string) {
-  const parsed = parsePersistedPanesRaw(raw)
-  if (!parsed) return
 
+  // Hydrate panes
   const state = store.getState()
   const localActiveByTab = (state?.panes?.activePane || {}) as Record<string, string>
-
   const nextActive: Record<string, string> = {}
 
-  for (const [tabId, node] of Object.entries(parsed.layouts || {})) {
+  for (const [tabId, node] of Object.entries(parsed.panes.layouts || {})) {
     const leafIds = collectPaneIdsSafe(node)
     if (leafIds.length === 0) continue
     const leafSet = new Set(leafIds)
@@ -92,7 +77,7 @@ function dispatchHydratePanesFromPersisted(store: StoreLike, raw: string) {
       continue
     }
 
-    const remoteDesired = parsed.activePane?.[tabId]
+    const remoteDesired = parsed.panes.activePane?.[tabId]
     if (typeof remoteDesired === 'string' && leafSet.has(remoteDesired)) {
       nextActive[tabId] = remoteDesired
       continue
@@ -103,10 +88,10 @@ function dispatchHydratePanesFromPersisted(store: StoreLike, raw: string) {
 
   store.dispatch({
     ...hydratePanes({
-      layouts: parsed.layouts as any,
+      layouts: parsed.panes.layouts as any,
       activePane: nextActive,
-      paneTitles: parsed.paneTitles,
-      paneTitleSetByUser: parsed.paneTitleSetByUser,
+      paneTitles: parsed.panes.paneTitles,
+      paneTitleSetByUser: parsed.panes.paneTitleSetByUser,
     } as any),
     meta: { skipPersist: true, source: 'cross-tab' },
   })
@@ -164,54 +149,27 @@ function handleIncomingRaw(
   key: string,
   raw: string,
   previousRaw?: string,
-  dedupeCheck?: (key: string, raw: string) => boolean,
 ) {
-  if (key === TABS_STORAGE_KEY) {
-    dispatchHydrateTabsFromPersisted(store, raw)
-    // Also hydrate panes from localStorage to keep tabs+panes atomic.
-    // The writing tab's flush() wrote both synchronously, so panes data
-    // is already in localStorage even if the panes event hasn't arrived yet.
-    readAndHydratePairedKey(store, PANES_STORAGE_KEY, dedupeCheck)
-  } else if (key === PANES_STORAGE_KEY) {
-    dispatchHydratePanesFromPersisted(store, raw)
-    readAndHydratePairedKey(store, TABS_STORAGE_KEY, dedupeCheck)
+  if (key === LAYOUT_STORAGE_KEY) {
+    dispatchHydrateLayoutFromPersisted(store, raw)
   } else if (key === BROWSER_PREFERENCES_STORAGE_KEY) {
     dispatchHydrateBrowserPreferencesFromPersisted(store, raw, previousRaw)
   }
 }
 
-function readAndHydratePairedKey(
-  store: StoreLike,
-  key: string,
-  dedupeCheck?: (key: string, raw: string) => boolean,
-) {
-  const raw = localStorage.getItem(key)
-  if (typeof raw !== 'string') return
-  if (dedupeCheck && !dedupeCheck(key, raw)) return
-  if (key === TABS_STORAGE_KEY) {
-    dispatchHydrateTabsFromPersisted(store, raw)
-  } else if (key === PANES_STORAGE_KEY) {
-    dispatchHydratePanesFromPersisted(store, raw)
-  }
-}
-
 export function installCrossTabSync(store: StoreLike): () => void {
   if (typeof window === 'undefined') return () => {}
 
   // Storage events and BroadcastChannel can both deliver the same persisted payload.
   // Dedupe by exact raw value so we don't hydrate twice.
   const lastProcessedRawByKey = new Map<string, string>()
-  for (const key of [TABS_STORAGE_KEY, PANES_STORAGE_KEY, BROWSER_PREFERENCES_STORAGE_KEY]) {
+  for (const key of [LAYOUT_STORAGE_KEY, BROWSER_PREFERENCES_STORAGE_KEY]) {
     const existingRaw = localStorage.getItem(key)
     if (typeof existingRaw === 'string') {
       lastProcessedRawByKey.set(key, existingRaw)
     }
   }
 
-  // tryDedupeAndMark is passed into handleIncomingRaw so that when a tabs event
-  // triggers a paired panes read from localStorage (or vice versa), the paired
-  // key also goes through dedup. This prevents the later StorageEvent for the
-  // paired key from re-hydrating what we already processed eagerly.
   const tryDedupeAndMark = (key: string, raw: string): boolean => {
     if (lastProcessedRawByKey.get(key) === raw) return false
     lastProcessedRawByKey.set(key, raw)
@@ -221,7 +179,7 @@ export function installCrossTabSync(store: StoreLike): () => void {
   const handleIncomingRawDeduped = (key: string, raw: string) => {
     const previousRaw = lastProcessedRawByKey.get(key)
     if (!tryDedupeAndMark(key, raw)) return
-    handleIncomingRaw(store, key, raw, previousRaw, tryDedupeAndMark)
+    handleIncomingRaw(store, key, raw, previousRaw)
   }
 
   // Keep dedupe state in sync with local writes too. Otherwise, if we process a remote raw,
@@ -229,8 +187,7 @@ export function installCrossTabSync(store: StoreLike): () => void {
   // could be incorrectly ignored.
   const unsubscribeLocal = onPersistBroadcast((msg) => {
     if (
-      msg.key !== TABS_STORAGE_KEY
-      && msg.key !== PANES_STORAGE_KEY
+      msg.key !== LAYOUT_STORAGE_KEY
       && msg.key !== BROWSER_PREFERENCES_STORAGE_KEY
     ) {
       return
@@ -242,8 +199,7 @@ export function installCrossTabSync(store: StoreLike): () => void {
     if (e.storageArea && e.storageArea !== localStorage) return
     const key = e.key
     if (
-      key !== TABS_STORAGE_KEY
-      && key !== PANES_STORAGE_KEY
+      key !== LAYOUT_STORAGE_KEY
       && key !== BROWSER_PREFERENCES_STORAGE_KEY
     ) {
       return
diff --git a/src/store/panesSlice.ts b/src/store/panesSlice.ts
index 28c54563..8fc92277 100644
--- a/src/store/panesSlice.ts
+++ b/src/store/panesSlice.ts
@@ -4,9 +4,8 @@ import type { PanesState, PaneContent, PaneContentInput, PaneNode, PaneRefreshRe
 import { derivePaneTitle } from '@/lib/derivePaneTitle'
 import { isValidClaudeSessionId } from '@/lib/claude-session-id'
 import { buildPaneRefreshTarget, paneRefreshTargetMatchesContent } from '@/lib/pane-utils'
-import { loadPersistedPanes } from './persistMiddleware.js'
+import { loadPersistedPanes, loadPersistedTabs } from './persistMiddleware.js'
 import { hasPaneTreeShape, isWellFormedPaneTree } from './paneTreeValidation.js'
-import { TABS_STORAGE_KEY } from './storage-keys'
 import { createLogger } from '@/lib/client-logger'
 
 
@@ -105,10 +104,9 @@ function normalizePaneContent(
  */
 function cleanOrphanedLayouts(state: PanesState): PanesState {
   try {
-    const rawTabs = localStorage.getItem(TABS_STORAGE_KEY)
-    if (!rawTabs) return state
-    const parsedTabs = JSON.parse(rawTabs)
-    const tabs = parsedTabs?.tabs?.tabs
+    const persistedTabs = loadPersistedTabs()
+    if (!persistedTabs) return state
+    const tabs = persistedTabs?.tabs?.tabs
     if (!Array.isArray(tabs)) return state
 
     const tabIds = new Set(tabs.map((t: any) => t?.id).filter(Boolean))
diff --git a/src/store/persistMiddleware.ts b/src/store/persistMiddleware.ts
index c370adc8..ad7d8037 100644
--- a/src/store/persistMiddleware.ts
+++ b/src/store/persistMiddleware.ts
@@ -5,8 +5,8 @@ import type { Tab } from './types'
 import { nanoid } from 'nanoid'
 import { broadcastPersistedRaw } from './persistBroadcast'
 import { isWellFormedPaneTree } from './paneTreeValidation.js'
-import { PANES_SCHEMA_VERSION } from './persistedState.js'
-import { PANES_STORAGE_KEY, TABS_STORAGE_KEY } from './storage-keys'
+import { PANES_SCHEMA_VERSION, LAYOUT_SCHEMA_VERSION, parsePersistedLayoutRaw, parsePersistedTabsRaw, parsePersistedPanesRaw } from './persistedState.js'
+import { LAYOUT_STORAGE_KEY, PANES_STORAGE_KEY, TABS_STORAGE_KEY } from './storage-keys'
 import { createLogger } from '@/lib/client-logger'
 
 
@@ -67,15 +67,56 @@ export function resetPersistedPanesCacheForTests() {
   cachedPersistedPanes = undefined
 }
 
-export function loadPersistedTabs(): any | null {
+import { migrateV2ToV3 } from './persistedState.js'
+
+let cachedPersistedLayout: { tabs: any; panes: any; tombstones: any } | null | undefined
+
+/**
+ * Load the combined layout from v3 key, or migrate from v2 keys.
+ * Cached so both tabs and panes loading see the same data.
+ */
+export function loadPersistedLayout(): typeof cachedPersistedLayout {
+  if (cachedPersistedLayout !== undefined) return cachedPersistedLayout
+
   try {
-    const raw = localStorage.getItem(TABS_STORAGE_KEY)
-    if (!raw) return null
-    const parsed = JSON.parse(raw)
-    return parsed
+    const raw = localStorage.getItem(LAYOUT_STORAGE_KEY)
+    if (raw) {
+      const layoutParsed = parsePersistedLayoutRaw(raw)
+      if (layoutParsed) {
+        cachedPersistedLayout = {
+          tabs: { tabs: layoutParsed.tabs },
+          panes: layoutParsed.panes,
+          tombstones: layoutParsed.tombstones,
+        }
+        return cachedPersistedLayout
+      }
+    }
+
+    // Try migration from v2 keys
+    const migrated = migrateV2ToV3()
+    if (migrated) {
+      cachedPersistedLayout = {
+        tabs: { tabs: migrated.tabs },
+        panes: migrated.panes,
+        tombstones: migrated.tombstones,
+      }
+      return cachedPersistedLayout
+    }
   } catch {
-    return null
+    // ignore
   }
+
+  cachedPersistedLayout = null
+  return null
+}
+
+export function resetPersistedLayoutCacheForTests() {
+  cachedPersistedLayout = undefined
+}
+
+export function loadPersistedTabs(): any | null {
+  const layout = loadPersistedLayout()
+  return layout?.tabs ?? null
 }
 
 /**
@@ -201,15 +242,32 @@ export function loadPersistedPanes(): any | null {
   // Memoize: legacy migrations generate nanoid() values, so both callers
   // (panesSlice and terminal-restore) must see the same result.
   if (cachedPersistedPanes !== undefined) return cachedPersistedPanes
-  cachedPersistedPanes = loadPersistedPanesUncached()
+
+  // Try the combined v3 layout first
+  const layout = loadPersistedLayout()
+  if (layout?.panes) {
+    cachedPersistedPanes = migratePanesData(layout.panes)
+    return cachedPersistedPanes
+  }
+
+  // Fall back to v2 panes key
+  cachedPersistedPanes = loadPersistedPanesFromV2Key()
   return cachedPersistedPanes
 }
 
-function loadPersistedPanesUncached(): any | null {
+function loadPersistedPanesFromV2Key(): any | null {
   try {
     const raw = localStorage.getItem(PANES_STORAGE_KEY)
     if (!raw) return null
     const parsed = JSON.parse(raw)
+    return migratePanesData(parsed)
+  } catch {
+    return null
+  }
+}
+
+function migratePanesData(parsed: any): any | null {
+  try {
 
     // Check if migration needed
     const currentVersion = parsed.version || 1
@@ -322,30 +380,24 @@ export const persistMiddleware: Middleware<{}, PersistState> = (store) => {
 
     const state = store.getState()
 
-    if (tabsDirty) {
-      const tabsPayload = {
-        tabs: {
-          // Persist only stable tab state. Keep ephemeral UI fields out of storage.
-          activeTabId: state.tabs.activeTabId,
-          tabs: state.tabs.tabs.map(stripTabVolatileFields),
-        },
-      }
-
-      try {
-        const raw = JSON.stringify(tabsPayload)
-        localStorage.setItem(TABS_STORAGE_KEY, raw)
-        broadcastPersistedRaw(TABS_STORAGE_KEY, raw)
-      } catch {
-        // ignore quota
-      }
-    }
+    try {
+      // Prune tombstones older than 1 hour
+      const TOMBSTONE_MAX_AGE_MS = 60 * 60 * 1000
+      const tombstoneCutoff = Date.now() - TOMBSTONE_MAX_AGE_MS
+      const tombstones = (state.tabs.tombstones || []).filter((t: { deletedAt: number }) => t.deletedAt > tombstoneCutoff)
 
-    if (panesDirty) {
-      try {
-        const sanitizedLayouts: Record<string, any> = {}
+      const sanitizedLayouts: Record<string, any> = {}
+      if (state.panes?.layouts) {
         for (const [tabId, node] of Object.entries(state.panes.layouts)) {
           sanitizedLayouts[tabId] = stripEditorContentFromNode(node)
         }
+      }
+
+      let persistablePanesSection: Record<string, any> = {
+        layouts: sanitizedLayouts,
+        version: PANES_SCHEMA_VERSION,
+      }
+      if (state.panes) {
         const {
           renameRequestTabId: _rrt,
           renameRequestPaneId: _rrp,
@@ -353,17 +405,28 @@ export const persistMiddleware: Middleware<{}, PersistState> = (store) => {
           refreshRequestsByPane: _rrbp,
           ...persistablePanes
         } = state.panes
-        const panesPayload = {
+        persistablePanesSection = {
           ...persistablePanes,
           layouts: sanitizedLayouts,
           version: PANES_SCHEMA_VERSION,
         }
-        const panesJson = JSON.stringify(panesPayload)
-        localStorage.setItem(PANES_STORAGE_KEY, panesJson)
-        broadcastPersistedRaw(PANES_STORAGE_KEY, panesJson)
-      } catch (err) {
-        log.error('Failed to save to localStorage:', err)
       }
+
+      const layoutPayload = {
+        version: LAYOUT_SCHEMA_VERSION,
+        tabs: {
+          activeTabId: state.tabs.activeTabId,
+          tabs: state.tabs.tabs.map(stripTabVolatileFields),
+        },
+        panes: persistablePanesSection,
+        tombstones,
+      }
+
+      const raw = JSON.stringify(layoutPayload)
+      localStorage.setItem(LAYOUT_STORAGE_KEY, raw)
+      broadcastPersistedRaw(LAYOUT_STORAGE_KEY, raw)
+    } catch (err) {
+      log.error('Failed to save to localStorage:', err)
     }
 
     tabsDirty = false
diff --git a/src/store/persistedState.ts b/src/store/persistedState.ts
index e3daf187..60bada0a 100644
--- a/src/store/persistedState.ts
+++ b/src/store/persistedState.ts
@@ -1,6 +1,7 @@
 import { z } from 'zod'
+import { LAYOUT_STORAGE_KEY, TABS_STORAGE_KEY, PANES_STORAGE_KEY } from './storage-keys'
 
-export { TABS_STORAGE_KEY, PANES_STORAGE_KEY } from './storage-keys'
+export { LAYOUT_STORAGE_KEY, TABS_STORAGE_KEY, PANES_STORAGE_KEY }
 
 export const TABS_SCHEMA_VERSION = 1
 export const PANES_SCHEMA_VERSION = 6
@@ -24,14 +25,21 @@ const zPersistedTabsState = z.object({
   tabs: z.array(zTab),
 }).passthrough()
 
+const zTombstone = z.object({
+  id: z.string(),
+  deletedAt: z.number(),
+})
+
 const zPersistedTabsPayload = z.object({
   version: z.number().optional(),
   tabs: zPersistedTabsState,
+  tombstones: z.array(zTombstone).optional(),
 }).passthrough()
 
 export type ParsedPersistedTabs = {
   version: number
   tabs: z.infer<typeof zPersistedTabsState>
+  tombstones: Array<{ id: string; deletedAt: number }>
 }
 
 export function parsePersistedTabsRaw(raw: string): ParsedPersistedTabs | null {
@@ -54,6 +62,7 @@ export function parsePersistedTabsRaw(raw: string): ParsedPersistedTabs | null {
       ...res.data.tabs,
       activeTabId: res.data.tabs.activeTabId ?? null,
     },
+    tombstones: res.data.tombstones || [],
   }
 }
 
@@ -101,3 +110,106 @@ export function parsePersistedPanesRaw(raw: string): ParsedPersistedPanes | null
     paneTitleSetByUser: (res.data.paneTitleSetByUser || {}) as Record<string, Record<string, boolean>>,
   }
 }
+
+// --- Combined layout key (v3) ---
+
+export const LAYOUT_SCHEMA_VERSION = 3
+
+const zPersistedLayoutPayload = z.object({
+  version: z.number(),
+  tabs: zPersistedTabsState,
+  panes: zPersistedPanesPayload,
+  tombstones: z.array(zTombstone).optional(),
+}).passthrough()
+
+export type ParsedPersistedLayout = {
+  version: number
+  tabs: z.infer<typeof zPersistedTabsState>
+  panes: ParsedPersistedPanes
+  tombstones: Array<{ id: string; deletedAt: number }>
+}
+
+export function parsePersistedLayoutRaw(raw: string): ParsedPersistedLayout | null {
+  let parsed: unknown
+  try {
+    parsed = JSON.parse(raw)
+  } catch {
+    return null
+  }
+
+  const res = zPersistedLayoutPayload.safeParse(parsed)
+  if (!res.success) return null
+
+  const panes = res.data.panes
+  let panesVersion = typeof panes.version === 'number' ? panes.version : 1
+  if (panesVersion < 1) panesVersion = 1
+
+  return {
+    version: res.data.version,
+    tabs: {
+      ...res.data.tabs,
+      activeTabId: res.data.tabs.activeTabId ?? null,
+    },
+    panes: {
+      version: panesVersion,
+      layouts: (panes.layouts || {}) as Record<string, unknown>,
+      activePane: (panes.activePane || {}) as Record<string, string>,
+      paneTitles: (panes.paneTitles || {}) as Record<string, Record<string, string>>,
+      paneTitleSetByUser: (panes.paneTitleSetByUser || {}) as Record<string, Record<string, boolean>>,
+    },
+    tombstones: res.data.tombstones || [],
+  }
+}
+
+/**
+ * Migrate from separate v2 tabs+panes keys to the combined v3 layout key.
+ * Returns the parsed v3 layout, or null if no v2 data existed.
+ */
+export function migrateV2ToV3(): ParsedPersistedLayout | null {
+  const tabsKey = TABS_STORAGE_KEY
+  const panesKey = PANES_STORAGE_KEY
+  const layoutKey = LAYOUT_STORAGE_KEY
+
+  const tabsRaw = localStorage.getItem(tabsKey)
+  if (!tabsRaw) return null
+
+  const tabsParsed = parsePersistedTabsRaw(tabsRaw)
+  if (!tabsParsed) return null
+
+  const panesRaw = localStorage.getItem(panesKey)
+  const panesParsed = panesRaw ? parsePersistedPanesRaw(panesRaw) : null
+
+  const emptyPanes: ParsedPersistedPanes = {
+    version: PANES_SCHEMA_VERSION,
+    layouts: {},
+    activePane: {},
+    paneTitles: {},
+    paneTitleSetByUser: {},
+  }
+
+  const layout: ParsedPersistedLayout = {
+    version: LAYOUT_SCHEMA_VERSION,
+    tabs: tabsParsed.tabs,
+    panes: panesParsed || emptyPanes,
+    tombstones: tabsParsed.tombstones,
+  }
+
+  // Write v3 key and clean up v2 keys
+  const v3Payload = {
+    version: LAYOUT_SCHEMA_VERSION,
+    tabs: layout.tabs,
+    panes: {
+      version: layout.panes.version,
+      layouts: layout.panes.layouts,
+      activePane: layout.panes.activePane,
+      paneTitles: layout.panes.paneTitles,
+      paneTitleSetByUser: layout.panes.paneTitleSetByUser,
+    },
+    tombstones: layout.tombstones,
+  }
+  localStorage.setItem(layoutKey, JSON.stringify(v3Payload))
+  localStorage.removeItem(tabsKey)
+  localStorage.removeItem(panesKey)
+
+  return layout
+}
diff --git a/src/store/selectors/paneTerminalSelectors.ts b/src/store/selectors/paneTerminalSelectors.ts
new file mode 100644
index 00000000..4e76d5ca
--- /dev/null
+++ b/src/store/selectors/paneTerminalSelectors.ts
@@ -0,0 +1,65 @@
+// Selectors that derive terminal IDs from pane tree layouts,
+// replacing direct reads of the legacy Tab.terminalId field.
+
+import type { RootState } from '../store'
+import type { PaneNode } from '../paneTypes'
+import { collectTerminalIds, findPaneContent } from '@/lib/pane-utils'
+
+/**
+ * Collect all terminal IDs from a tab's pane layout tree.
+ * Returns an empty array if no layout exists or no terminals are assigned.
+ */
+export function selectTerminalIdsForTab(state: RootState, tabId: string): string[] {
+  const layout = state.panes.layouts[tabId]
+  if (!layout) return []
+  return collectTerminalIds(layout)
+}
+
+/**
+ * Return the "primary" terminal ID for a tab: the active pane's terminalId
+ * if available, otherwise the first leaf's terminalId.
+ */
+export function selectPrimaryTerminalIdForTab(state: RootState, tabId: string): string | undefined {
+  const layout = state.panes.layouts[tabId]
+  if (!layout) return undefined
+
+  // Try active pane first
+  const activePaneId = state.panes.activePane[tabId]
+  if (activePaneId) {
+    const content = findPaneContent(layout, activePaneId)
+    if (content?.kind === 'terminal' && content.terminalId) {
+      return content.terminalId
+    }
+  }
+
+  // Fall back to first leaf with a terminal ID
+  return findFirstTerminalId(layout)
+}
+
+/**
+ * Reverse lookup: find the tab ID that owns a given terminal ID
+ * by searching all pane layout trees.
+ */
+export function selectTabIdByTerminalId(state: RootState, terminalId: string): string | undefined {
+  for (const [tabId, layout] of Object.entries(state.panes.layouts)) {
+    if (nodeContainsTerminalId(layout, terminalId)) {
+      return tabId
+    }
+  }
+  return undefined
+}
+
+function findFirstTerminalId(node: PaneNode): string | undefined {
+  if (node.type === 'leaf') {
+    return node.content.kind === 'terminal' ? node.content.terminalId : undefined
+  }
+  return findFirstTerminalId(node.children[0]) ?? findFirstTerminalId(node.children[1])
+}
+
+function nodeContainsTerminalId(node: PaneNode, terminalId: string): boolean {
+  if (node.type === 'leaf') {
+    return node.content.kind === 'terminal' && node.content.terminalId === terminalId
+  }
+  return nodeContainsTerminalId(node.children[0], terminalId)
+    || nodeContainsTerminalId(node.children[1], terminalId)
+}
diff --git a/src/store/sessionsSlice.ts b/src/store/sessionsSlice.ts
index 8006f225..cf38c5ea 100644
--- a/src/store/sessionsSlice.ts
+++ b/src/store/sessionsSlice.ts
@@ -411,12 +411,6 @@ export const sessionsSlice = createSlice({
       if (expanded) state.expandedProjects.add(projectPath)
       else state.expandedProjects.delete(projectPath)
     },
-    collapseAll: (state) => {
-      state.expandedProjects = new Set()
-    },
-    expandAll: (state) => {
-      state.expandedProjects = new Set(state.projects.map((p) => p.projectPath))
-    },
   },
 })
 
@@ -438,8 +432,6 @@ export const {
   setLoadingMore,
   toggleProjectExpanded,
   setProjectExpanded,
-  collapseAll,
-  expandAll,
 } =
   sessionsSlice.actions
 
diff --git a/src/store/storage-keys.ts b/src/store/storage-keys.ts
index 6350716e..63462fde 100644
--- a/src/store/storage-keys.ts
+++ b/src/store/storage-keys.ts
@@ -1,4 +1,5 @@
 export const STORAGE_KEYS = {
+  layout: 'freshell.layout.v3',
   tabs: 'freshell.tabs.v2',
   panes: 'freshell.panes.v2',
   sessionActivity: 'freshell.sessionActivity.v2',
@@ -12,6 +13,7 @@ export const STORAGE_KEYS = {
   deviceDismissed: 'freshell.device-dismissed.v1',
 } as const
 
+export const LAYOUT_STORAGE_KEY = STORAGE_KEYS.layout
 export const TABS_STORAGE_KEY = STORAGE_KEYS.tabs
 export const PANES_STORAGE_KEY = STORAGE_KEYS.panes
 export const SESSION_ACTIVITY_STORAGE_KEY = STORAGE_KEYS.sessionActivity
diff --git a/src/store/tabRegistrySlice.ts b/src/store/tabRegistrySlice.ts
index 9568c36b..0d2e2ac2 100644
--- a/src/store/tabRegistrySlice.ts
+++ b/src/store/tabRegistrySlice.ts
@@ -304,9 +304,6 @@ export const tabRegistrySlice = createSlice({
     recordClosedTabSnapshot: (state, action: PayloadAction<RegistryTabRecord>) => {
       state.localClosed[action.payload.tabKey] = action.payload
     },
-    clearClosedTabSnapshot: (state, action: PayloadAction<string>) => {
-      delete state.localClosed[action.payload]
-    },
     pushReopenEntry: (state, action: PayloadAction<ClosedTabEntry>) => {
       state.reopenStack.push(action.payload)
       if (state.reopenStack.length > REOPEN_STACK_MAX) {
@@ -329,7 +326,6 @@ export const {
   setTabRegistrySnapshot,
   setTabRegistrySyncError,
   recordClosedTabSnapshot,
-  clearClosedTabSnapshot,
   pushReopenEntry,
   popReopenEntry,
 } = tabRegistrySlice.actions
diff --git a/src/store/tabRegistrySync.ts b/src/store/tabRegistrySync.ts
index dc971088..2c544eb6 100644
--- a/src/store/tabRegistrySync.ts
+++ b/src/store/tabRegistrySync.ts
@@ -96,7 +96,6 @@ function lifecycleSignature(state: RootState): string {
       title: tab.title,
       status: tab.status,
       mode: tab.mode,
-      terminalId: tab.terminalId,
       titleSetByUser: !!tab.titleSetByUser,
     })),
     panes: Object.entries(state.panes.layouts).map(([tabId, node]) => ({
diff --git a/src/store/tabsSlice.ts b/src/store/tabsSlice.ts
index 5ad624a9..c4ea3f2b 100644
--- a/src/store/tabsSlice.ts
+++ b/src/store/tabsSlice.ts
@@ -17,19 +17,41 @@ import {
 } from '@/lib/tab-registry-snapshot'
 import { UNKNOWN_SERVER_INSTANCE_ID } from './tabRegistryConstants'
 import type { RootState } from './store'
-import { TABS_STORAGE_KEY } from './storage-keys'
+import { selectTabIdByTerminalId } from './selectors/paneTerminalSelectors'
+import { loadPersistedLayout } from './persistMiddleware'
 import { createLogger } from '@/lib/client-logger'
 import { mergeSessionMetadataByKey } from '@/lib/session-metadata'
 
 
 const log = createLogger('TabsSlice')
 
+export type Tombstone = { id: string; deletedAt: number }
+
 export interface TabsState {
   tabs: Tab[]
   activeTabId: string | null
   // Ephemeral UI signal: request TabBar to enter inline rename mode for a tab.
   // This must never be persisted.
   renameRequestTabId: string | null
+  // IDs of tabs that were explicitly closed. Prevents resurrection during cross-tab merge.
+  tombstones: Tombstone[]
+}
+
+function migrateTabFields(t: Tab): Tab {
+  const legacyClaudeSessionId = (t as any).claudeSessionId as string | undefined
+  // Strip legacy terminalId field from persisted data
+  const { terminalId: _legacyTerminalId, ...rest } = t as Tab & { terminalId?: unknown }
+  return {
+    ...rest,
+    codingCliSessionId: t.codingCliSessionId || legacyClaudeSessionId,
+    codingCliProvider: t.codingCliProvider || (legacyClaudeSessionId ? 'claude' : undefined),
+    createdAt: t.createdAt || Date.now(),
+    createRequestId: (t as any).createRequestId || t.id,
+    status: t.status || 'creating',
+    mode: t.mode || 'shell',
+    shell: t.shell || 'system',
+    lastInputAt: t.lastInputAt,
+  }
 }
 
 // Load persisted tabs state directly at module initialization time
@@ -39,40 +61,27 @@ function loadInitialTabsState(): TabsState {
     tabs: [],
     activeTabId: null,
     renameRequestTabId: null,
+    tombstones: [],
   }
 
   try {
-    const raw = localStorage.getItem(TABS_STORAGE_KEY)
-    if (!raw) return defaultState
-    const parsed = JSON.parse(raw)
-    // The persisted format is { tabs: TabsState }
-    const tabsState = parsed?.tabs as Partial<TabsState> | undefined
+    const layout = loadPersistedLayout()
+    if (!layout) return defaultState
+
+    const tabsState = layout.tabs?.tabs as Partial<TabsState> | undefined
     if (!Array.isArray(tabsState?.tabs)) return defaultState
 
-    log.debug('Loaded initial state from localStorage:', tabsState.tabs.map((t) => t.id))
-
-    // Apply same transformations as hydrateTabs to ensure consistency
-    const mappedTabs = tabsState.tabs.map((t: Tab) => {
-      const legacyClaudeSessionId = (t as any).claudeSessionId as string | undefined
-      return {
-        ...t,
-        codingCliSessionId: t.codingCliSessionId || legacyClaudeSessionId,
-        codingCliProvider: t.codingCliProvider || (legacyClaudeSessionId ? 'claude' : undefined),
-        createdAt: t.createdAt || Date.now(),
-        createRequestId: (t as any).createRequestId || t.id,
-        status: t.status || 'creating',
-        mode: t.mode || 'shell',
-        shell: t.shell || 'system',
-        lastInputAt: t.lastInputAt,
-      }
-    })
+    log.debug('Loaded initial state from localStorage:', tabsState.tabs.map((t: Tab) => t.id))
+
+    const mappedTabs = tabsState.tabs.map(migrateTabFields)
     const desired = tabsState.activeTabId
-    const has = desired && mappedTabs.some((t) => t.id === desired)
+    const has = desired && mappedTabs.some((t: Tab) => t.id === desired)
 
     return {
       tabs: mappedTabs,
       activeTabId: has ? desired! : (mappedTabs[0]?.id ?? null),
       renameRequestTabId: null,
+      tombstones: Array.isArray(layout.tombstones) ? layout.tombstones : [],
     }
   } catch (err) {
     log.error('Failed to load from localStorage:', err)
@@ -86,7 +95,6 @@ type AddTabPayload = {
   id?: string
   title?: string
   description?: string
-  terminalId?: string
   codingCliSessionId?: string
   codingCliProvider?: CodingCliProviderName
   claudeSessionId?: string
@@ -119,7 +127,6 @@ export const tabsSlice = createSlice({
         createRequestId: payload.createRequestId || id,
         title: payload.title || `Tab ${state.tabs.length + 1}`,
         description: payload.description,
-        terminalId: payload.terminalId,
         codingCliSessionId,
         codingCliProvider,
         claudeSessionId: payload.claudeSessionId,
@@ -130,6 +137,7 @@ export const tabsSlice = createSlice({
         resumeSessionId: payload.resumeSessionId,
         sessionMetadataByKey: payload.sessionMetadataByKey,
         createdAt: Date.now(),
+        updatedAt: Date.now(),
         titleSetByUser: payload.titleSetByUser,
         lastInputAt: undefined,
       }
@@ -147,7 +155,10 @@ export const tabsSlice = createSlice({
     },
     updateTab: (state, action: PayloadAction<{ id: string; updates: Partial<Tab> }>) => {
       const tab = state.tabs.find((t) => t.id === action.payload.id)
-      if (tab) Object.assign(tab, action.payload.updates)
+      if (tab) {
+        Object.assign(tab, action.payload.updates)
+        tab.updatedAt = Date.now()
+      }
     },
     removeTab: (state, action: PayloadAction<string>) => {
       const removedTabId = action.payload
@@ -155,6 +166,8 @@ export const tabsSlice = createSlice({
       const wasActive = state.activeTabId === removedTabId
 
       state.tabs = state.tabs.filter((t) => t.id !== removedTabId)
+      if (!state.tombstones) state.tombstones = []
+      state.tombstones.push({ id: removedTabId, deletedAt: Date.now() })
 
       if (wasActive) {
         if (state.tabs.length === 0) {
@@ -167,23 +180,55 @@ export const tabsSlice = createSlice({
       }
     },
     hydrateTabs: (state, action: PayloadAction<TabsState>) => {
-      // Basic sanity: ensure dates exist, status defaults.
-      state.tabs = (action.payload.tabs || []).map((t) => {
-        const legacyClaudeSessionId = (t as any).claudeSessionId as string | undefined
-        return {
-          ...t,
-          codingCliSessionId: t.codingCliSessionId || legacyClaudeSessionId,
-          codingCliProvider: t.codingCliProvider || (legacyClaudeSessionId ? 'claude' : undefined),
-          createdAt: t.createdAt || Date.now(),
-          createRequestId: (t as any).createRequestId || t.id,
-          status: t.status || 'creating',
-          mode: t.mode || 'shell',
-          shell: t.shell || 'system',
+      const remoteTabs = (action.payload.tabs || []).map(migrateTabFields)
+      const remoteTombstones: Tombstone[] = Array.isArray(action.payload.tombstones) ? action.payload.tombstones : []
+
+      // Union tombstones from both sides, deduped by ID
+      const tombstoneMap = new Map<string, number>()
+      for (const t of (state.tombstones || [])) tombstoneMap.set(t.id, Math.max(tombstoneMap.get(t.id) ?? 0, t.deletedAt))
+      for (const t of remoteTombstones) tombstoneMap.set(t.id, Math.max(tombstoneMap.get(t.id) ?? 0, t.deletedAt))
+      state.tombstones = Array.from(tombstoneMap, ([id, deletedAt]) => ({ id, deletedAt }))
+
+      const tombstoned = new Set(tombstoneMap.keys())
+      const localById = new Map(state.tabs.map((t) => [t.id, t]))
+      const remoteById = new Map(remoteTabs.map((t) => [t.id, t]))
+
+      // Build merged list: remote order for shared tabs, then local-only tabs appended
+      const merged: Tab[] = []
+      const seen = new Set<string>()
+
+      for (const remoteTab of remoteTabs) {
+        if (tombstoned.has(remoteTab.id)) continue
+        seen.add(remoteTab.id)
+        const localTab = localById.get(remoteTab.id)
+        if (localTab) {
+          // Both sides have this tab — resolve by updatedAt (remote wins ties)
+          merged.push((localTab.updatedAt ?? 0) > (remoteTab.updatedAt ?? 0) ? localTab : remoteTab)
+        } else {
+          merged.push(remoteTab)
         }
-      })
-      const desired = action.payload.activeTabId
-      const has = desired && state.tabs.some((t) => t.id === desired)
-      state.activeTabId = has ? desired! : (state.tabs[0]?.id ?? null)
+      }
+
+      // Append local-only tabs (not in remote, not tombstoned)
+      for (const localTab of state.tabs) {
+        if (seen.has(localTab.id) || tombstoned.has(localTab.id)) continue
+        if (!remoteById.has(localTab.id)) {
+          merged.push(localTab)
+        }
+      }
+
+      state.tabs = merged
+
+      // Prefer local activeTabId if it still exists in merged set
+      const localActive = state.activeTabId
+      const mergedIds = new Set(merged.map((t) => t.id))
+      if (localActive && mergedIds.has(localActive)) {
+        // keep local
+      } else {
+        const desired = action.payload.activeTabId
+        state.activeTabId = (desired && mergedIds.has(desired)) ? desired : (merged[0]?.id ?? null)
+      }
+
       state.renameRequestTabId = null
     },
     reorderTabs: (
@@ -448,7 +493,10 @@ export const openSessionTab = createAsyncThunk(
 
     if (terminalId) {
       if (!forceNew) {
-        const existingTab = state.tabs.tabs.find((t) => t.terminalId === terminalId)
+        const existingTabId = selectTabIdByTerminalId(state, terminalId)
+        const existingTab = existingTabId
+          ? state.tabs.tabs.find((t) => t.id === existingTabId)
+          : undefined
         if (existingTab) {
           updateExistingTabMetadata(existingTab)
           dispatch(setActiveTab(existingTab.id))
@@ -456,9 +504,10 @@ export const openSessionTab = createAsyncThunk(
         }
       }
       // Running terminals are always terminal panes (agent-chat uses SDK, not PTY)
+      const tabId = nanoid()
       dispatch(addTab({
+        id: tabId,
         title: title || getProviderLabel(resolvedProvider, extensions),
-        terminalId,
         status: 'running',
         mode: resolvedProvider,
         codingCliProvider: resolvedProvider,
@@ -466,6 +515,17 @@ export const openSessionTab = createAsyncThunk(
         resumeSessionId: sessionId,
         sessionMetadataByKey: buildSessionMetadataByKey(),
       }))
+      dispatch(initLayout({
+        tabId,
+        content: {
+          kind: 'terminal',
+          mode: resolvedProvider,
+          terminalId,
+          resumeSessionId: sessionId,
+          initialCwd: cwd,
+          status: 'running',
+        },
+      }))
       return
     }
 
diff --git a/src/store/types.ts b/src/store/types.ts
index 5f69ea0f..7737c914 100644
--- a/src/store/types.ts
+++ b/src/store/types.ts
@@ -49,7 +49,6 @@ export interface Tab {
   createRequestId: string
   title: string
   description?: string
-  terminalId?: string          // For shell mode
   codingCliSessionId?: string  // For coding CLI session view
   codingCliProvider?: CodingCliProviderName
   claudeSessionId?: string     // Legacy field (migrated to codingCliSessionId)
@@ -60,6 +59,7 @@ export interface Tab {
   resumeSessionId?: string     // Mirrored from pane content on session association; serves as fallback if pane layout is lost
   sessionMetadataByKey?: Record<string, SessionListMetadata>
   createdAt: number
+  updatedAt?: number
   titleSetByUser?: boolean     // If true, don't auto-update title
   lastInputAt?: number
 }
diff --git a/test/e2e-browser/perf/scenarios.ts b/test/e2e-browser/perf/scenarios.ts
index 15304598..9de55214 100644
--- a/test/e2e-browser/perf/scenarios.ts
+++ b/test/e2e-browser/perf/scenarios.ts
@@ -54,7 +54,7 @@ export const AUDIT_SCENARIOS: readonly AuditScenarioDefinition[] = [
       'terminal.attach.ready',
       'terminal.output',
       'terminal.output.gap',
-      'terminal.runtime.updated',
+
       'terminals.changed',
     ],
     buildUrl: ({ token }) => buildRootUrl(token),
@@ -87,7 +87,7 @@ export const AUDIT_SCENARIOS: readonly AuditScenarioDefinition[] = [
       'terminal.attach.ready',
       'terminal.output',
       'terminal.output.gap',
-      'terminal.runtime.updated',
+
       'terminals.changed',
     ],
     buildUrl: ({ token }) => buildRootUrl(token),
diff --git a/test/e2e/codex-activity-indicator-flow.test.tsx b/test/e2e/codex-activity-indicator-flow.test.tsx
index 7a78244e..e477340c 100644
--- a/test/e2e/codex-activity-indicator-flow.test.tsx
+++ b/test/e2e/codex-activity-indicator-flow.test.tsx
@@ -53,7 +53,6 @@ function renderHarness(options: RenderHarnessOptions = {}) {
     status: 'running',
     mode: 'codex',
     shell: 'system',
-    terminalId: 'term-live',
     createdAt: 1,
     ...options.tab,
   }
@@ -162,9 +161,8 @@ describe('codex activity indicator flow (e2e)', () => {
     expect(within(tabButton).getByTestId('pane-icon').getAttribute('class')).toContain('text-blue-500')
   })
 
-  it('falls back to the exact tab terminal id during single-pane rehydrate gaps', () => {
+  it('shows no activity when pane has no terminalId even during single-pane rehydrate gaps', () => {
     renderHarness({
-      tab: { terminalId: 'term-tab' },
       pane: { terminalId: undefined },
       codexActivity: {
         byTerminalId: {
@@ -177,16 +175,15 @@ describe('codex activity indicator flow (e2e)', () => {
     })
 
     const paneHeader = screen.getByRole('banner', { name: 'Pane: Codex Pane' })
-    expect(within(paneHeader).getByTestId('pane-icon').getAttribute('class')).toContain('text-blue-500')
+    expect(within(paneHeader).getByTestId('pane-icon').getAttribute('class') ?? '').not.toContain('text-blue-500')
 
     const tabButton = getVisibleSinglePaneTab()
-    expect(within(tabButton).getByTestId('pane-icon').getAttribute('class')).toContain('text-blue-500')
+    expect(within(tabButton).getByTestId('pane-icon').getAttribute('class') ?? '').not.toContain('text-blue-500')
   })
 
   it('never shows blue from resumeSessionId, sessionRef, cwd, or provider-only terminal meta fallbacks', () => {
     renderHarness({
       tab: {
-        terminalId: undefined,
         resumeSessionId: 'session-1',
       },
       pane: {
diff --git a/test/server/ws-terminal-create-reuse-running-claude.test.ts b/test/server/ws-terminal-create-reuse-running-claude.test.ts
index 5cd2a87d..c9e13a04 100644
--- a/test/server/ws-terminal-create-reuse-running-claude.test.ts
+++ b/test/server/ws-terminal-create-reuse-running-claude.test.ts
@@ -332,10 +332,9 @@ describe('terminal.create reuse running claude terminal', () => {
       await terminalsChangedPromise
 
       expect(registry.attachCalls).toHaveLength(0)
-      const attachMessagesPromise = waitForMessages(ws, [
+      const attachReadyPromise = waitForMessage(ws,
         (m) => m.type === 'terminal.attach.ready' && m.attachRequestId === 'reuse-1-attach',
-        (m) => m.type === 'terminal.runtime.updated' && m.terminalId === created.terminalId,
-      ])
+      )
       ws.send(JSON.stringify({
         type: 'terminal.attach',
         terminalId: created.terminalId,
@@ -344,15 +343,9 @@ describe('terminal.create reuse running claude terminal', () => {
         rows: 40,
         attachRequestId: 'reuse-1-attach',
       }))
-      const [ready, runtimeUpdated] = await attachMessagesPromise
+      const ready = await attachReadyPromise
 
       expect(ready.type).toBe('terminal.attach.ready')
-      expect(runtimeUpdated).toEqual(expect.objectContaining({
-        type: 'terminal.runtime.updated',
-        terminalId: created.terminalId,
-        status: 'running',
-        title: 'Shell',
-      }))
       expect(registry.attachCalls).toHaveLength(1)
       expect(registry.attachCalls[0]?.opts?.suppressOutput).toBe(true)
       expect(snapshotSpy).not.toHaveBeenCalled()
diff --git a/test/server/ws-terminal-create-reuse-running-codex.test.ts b/test/server/ws-terminal-create-reuse-running-codex.test.ts
index 4de63a5e..8f7605df 100644
--- a/test/server/ws-terminal-create-reuse-running-codex.test.ts
+++ b/test/server/ws-terminal-create-reuse-running-codex.test.ts
@@ -332,10 +332,9 @@ describe('terminal.create reuse running codex terminal', () => {
       expect(registry.attachCalls).toHaveLength(0)
       expect(registry.createCalls).toHaveLength(0)
 
-      const attachMessagesPromise = waitForMessages(ws, [
+      const attachReadyPromise = waitForMessage(ws,
         (m) => m.type === 'terminal.attach.ready' && m.attachRequestId === 'reuse-existing-codex-attach',
-        (m) => m.type === 'terminal.runtime.updated' && m.terminalId === created.terminalId,
-      ])
+      )
       ws.send(JSON.stringify({
         type: 'terminal.attach',
         terminalId: created.terminalId,
@@ -344,14 +343,8 @@ describe('terminal.create reuse running codex terminal', () => {
         rows: 40,
         attachRequestId: 'reuse-existing-codex-attach',
       }))
-      const [ready, runtimeUpdated] = await attachMessagesPromise
+      const ready = await attachReadyPromise
       expect(ready.headSeq).toBeGreaterThanOrEqual(0)
-      expect(runtimeUpdated).toEqual(expect.objectContaining({
-        type: 'terminal.runtime.updated',
-        terminalId: created.terminalId,
-        status: 'running',
-        title: 'Codex',
-      }))
       expect(registry.attachCalls).toHaveLength(1)
       expect(registry.attachCalls[0]?.terminalId).toBe('term-codex-existing')
     } finally {
diff --git a/test/server/ws-terminal-meta.test.ts b/test/server/ws-terminal-meta.test.ts
index c3a6b500..09efb6b1 100644
--- a/test/server/ws-terminal-meta.test.ts
+++ b/test/server/ws-terminal-meta.test.ts
@@ -131,30 +131,4 @@ describe('ws terminal metadata protocol', () => {
     ws.close()
   })
 
-  it('broadcasts terminal.runtime.updated payloads', async () => {
-    const ws = new WebSocket(`ws://127.0.0.1:${port}/ws`)
-    await new Promise<void>((resolve) => ws.on('open', () => resolve()))
-    ws.send(JSON.stringify({ type: 'hello', token: 'terminal-meta-token', protocolVersion: WS_PROTOCOL_VERSION }))
-    await waitForMessage(ws, (msg) => msg.type === 'ready')
-
-    wsHandler.broadcastTerminalRuntimeUpdated({
-      terminalId: 'term-1',
-      title: 'Shell',
-      status: 'running',
-      cwd: '/workspace/repo',
-      pid: 4242,
-    })
-
-    const updated = await waitForMessage(ws, (msg) => msg.type === 'terminal.runtime.updated')
-    expect(updated).toEqual({
-      type: 'terminal.runtime.updated',
-      terminalId: 'term-1',
-      revision: 1,
-      title: 'Shell',
-      status: 'running',
-      cwd: '/workspace/repo',
-      pid: 4242,
-    })
-    ws.close()
-  })
 })
diff --git a/test/unit/client/components/BackgroundSessions.test.tsx b/test/unit/client/components/BackgroundSessions.test.tsx
index 11171e0e..20763cb6 100644
--- a/test/unit/client/components/BackgroundSessions.test.tsx
+++ b/test/unit/client/components/BackgroundSessions.test.tsx
@@ -5,6 +5,7 @@ import { Provider } from 'react-redux'
 import { configureStore } from '@reduxjs/toolkit'
 import BackgroundSessions from '../../../../src/components/BackgroundSessions'
 import tabsReducer from '../../../../src/store/tabsSlice'
+import panesReducer from '../../../../src/store/panesSlice'
 import settingsReducer from '../../../../src/store/settingsSlice'
 import terminalDirectoryReducer from '../../../../src/store/terminalDirectorySlice'
 
@@ -33,6 +34,7 @@ function makeStore() {
   return configureStore({
     reducer: {
       tabs: tabsReducer,
+      panes: panesReducer,
       settings: settingsReducer,
       terminalDirectory: terminalDirectoryReducer,
     },
@@ -79,6 +81,15 @@ describe('BackgroundSessions', () => {
     expect(tabs).toHaveLength(1)
     expect(tabs[0].mode).toBe('codex')
     expect(tabs[0].resumeSessionId).toBe('codex-sess-abc')
-    expect(tabs[0].terminalId).toBe('term-codex-1')
+    // terminalId is in pane content, not on the tab
+    const layout = store.getState().panes.layouts[tabs[0].id]
+    expect(layout).toBeDefined()
+    expect(layout.type).toBe('leaf')
+    if (layout.type === 'leaf') {
+      expect(layout.content.kind).toBe('terminal')
+      if (layout.content.kind === 'terminal') {
+        expect(layout.content.terminalId).toBe('term-codex-1')
+      }
+    }
   })
 })
diff --git a/test/unit/client/components/ContextMenuProvider.test.tsx b/test/unit/client/components/ContextMenuProvider.test.tsx
index 3917554d..f4d4d69d 100644
--- a/test/unit/client/components/ContextMenuProvider.test.tsx
+++ b/test/unit/client/components/ContextMenuProvider.test.tsx
@@ -546,7 +546,6 @@ function createStoreWithTerminalPane() {
             mode: 'shell',
             shell: 'system',
             createdAt: 1,
-            terminalId: 'term-1',
           },
         ],
         activeTabId: 'tab-1',
@@ -1437,8 +1436,8 @@ describe('ContextMenuProvider', () => {
         expect(layout.content).toEqual({ kind: 'picker' })
       }
 
-      // Verify stale tab.terminalId is cleared
-      expect(store.getState().tabs.tabs[0].terminalId).toBeUndefined()
+      // Verify pane content no longer has the old terminal
+      // (tab.terminalId was removed; terminal ownership is in pane content only)
     })
 
   })
diff --git a/test/unit/client/components/Sidebar.test.tsx b/test/unit/client/components/Sidebar.test.tsx
index 3f9793fd..5fcca75c 100644
--- a/test/unit/client/components/Sidebar.test.tsx
+++ b/test/unit/client/components/Sidebar.test.tsx
@@ -1516,12 +1516,17 @@ describe('Sidebar Component - Session-Centric Display', () => {
       // Should navigate to terminal view
       expect(onNavigate).toHaveBeenCalledWith('terminal')
 
-      // Should create a new tab with the terminalId to attach
+      // Should create a new tab with the terminalId in pane content
       const state = store.getState()
       expect(state.tabs.tabs).toHaveLength(1)
-      expect(state.tabs.tabs[0].terminalId).toBe('orphan-terminal-id')
       expect(state.tabs.tabs[0].resumeSessionId).toBe(sessionId('session-running-no-tab'))
       expect(state.tabs.tabs[0].mode).toBe('claude')
+      // terminalId lives in pane content, not on the tab
+      const layout = state.panes.layouts[state.tabs.tabs[0].id]
+      expect(layout).toBeDefined()
+      if (layout?.type === 'leaf' && layout.content.kind === 'terminal') {
+        expect(layout.content.terminalId).toBe('orphan-terminal-id')
+      }
     })
   })
 
diff --git a/test/unit/client/components/TabBar.test.tsx b/test/unit/client/components/TabBar.test.tsx
index 8d470758..6baa916e 100644
--- a/test/unit/client/components/TabBar.test.tsx
+++ b/test/unit/client/components/TabBar.test.tsx
@@ -368,12 +368,11 @@ describe('TabBar', () => {
       expect(blueIcons).toHaveLength(0)
     })
 
-    it('falls back to the exact tab terminal id for a single-pane rehydrate gap', () => {
+    it('shows no activity when pane has no terminalId during rehydrate gap', () => {
       const tab = createTab({
         id: 'tab-rehydrate',
         title: 'Rehydrate Gap',
         mode: 'codex',
-        terminalId: 'term-tab',
       })
       const store = createStore(
         { tabs: [tab], activeTabId: 'tab-rehydrate' },
@@ -410,7 +409,7 @@ describe('TabBar', () => {
       const blueIcons = within(tabElement).getAllByTestId('pane-icon')
         .filter((icon) => icon.getAttribute('class')?.includes('text-blue-500'))
 
-      expect(blueIcons.length).toBeGreaterThan(0)
+      expect(blueIcons).toHaveLength(0)
     })
   })
 
@@ -556,17 +555,33 @@ describe('TabBar', () => {
       expect(state.tabs[0].id).toBe('tab-2')
     })
 
-    it('close button sends detach message when tab has terminalId', () => {
+    it('close button sends detach message when pane has terminalId', () => {
       const tab = createTab({
         id: 'tab-1',
         title: 'Tab 1',
-        terminalId: 'term-123',
       })
 
-      const store = createStore({
-        tabs: [tab],
-        activeTabId: 'tab-1',
-      })
+      const store = createStore(
+        { tabs: [tab], activeTabId: 'tab-1' },
+        {},
+        {
+          layouts: {
+            'tab-1': {
+              type: 'leaf',
+              id: 'pane-1',
+              content: {
+                kind: 'terminal',
+                mode: 'shell',
+                shell: 'system',
+                status: 'running',
+                createRequestId: 'req-pane-1',
+                terminalId: 'term-123',
+              },
+            },
+          },
+          activePane: { 'tab-1': 'pane-1' },
+        },
+      )
 
       renderWithStore(<TabBar />, store)
 
@@ -583,13 +598,29 @@ describe('TabBar', () => {
       const tab = createTab({
         id: 'tab-1',
         title: 'Tab 1',
-        terminalId: 'term-456',
       })
 
-      const store = createStore({
-        tabs: [tab],
-        activeTabId: 'tab-1',
-      })
+      const store = createStore(
+        { tabs: [tab], activeTabId: 'tab-1' },
+        {},
+        {
+          layouts: {
+            'tab-1': {
+              type: 'leaf',
+              id: 'pane-1',
+              content: {
+                kind: 'terminal',
+                mode: 'shell',
+                shell: 'system',
+                status: 'running',
+                createRequestId: 'req-pane-1',
+                terminalId: 'term-456',
+              },
+            },
+          },
+          activePane: { 'tab-1': 'pane-1' },
+        },
+      )
 
       renderWithStore(<TabBar />, store)
 
@@ -606,7 +637,6 @@ describe('TabBar', () => {
       const tab = createTab({
         id: 'tab-1',
         title: 'Tab 1',
-        terminalId: 'term-stale',
       })
 
       const store = createStore(
diff --git a/test/unit/client/components/TabContent.test.tsx b/test/unit/client/components/TabContent.test.tsx
index 6348b620..a182cdaf 100644
--- a/test/unit/client/components/TabContent.test.tsx
+++ b/test/unit/client/components/TabContent.test.tsx
@@ -25,7 +25,6 @@ vi.mock('@/components/SessionView', () => ({
 interface TabConfig {
   id: string
   mode: string
-  terminalId?: string
   codingCliSessionId?: string
   resumeSessionId?: string
   sessionMetadataByKey?: Record<string, unknown>
@@ -56,7 +55,6 @@ function createStore(tabs: TabConfig[], options: StoreOptions = {}) {
           mode: t.mode as any,
           status: 'running' as const,
           title: 'Test',
-          terminalId: t.terminalId,
           codingCliSessionId: t.codingCliSessionId,
           resumeSessionId: t.resumeSessionId,
           sessionMetadataByKey: t.sessionMetadataByKey,
@@ -85,27 +83,8 @@ describe('TabContent', () => {
     cleanup()
   })
 
-  describe('terminalId passthrough', () => {
-    it('passes terminalId to PaneLayout defaultContent when tab has terminalId', () => {
-      const store = createStore([{ id: 'tab-1', mode: 'shell', terminalId: 'existing-terminal-123' }])
-
-      render(
-        <Provider store={store}>
-          <TabContent tabId="tab-1" />
-        </Provider>
-      )
-
-      expect(mockPaneLayout).toHaveBeenCalledWith(
-        expect.objectContaining({
-          defaultContent: expect.objectContaining({
-            terminalId: 'existing-terminal-123',
-          }),
-        }),
-        expect.anything()
-      )
-    })
-
-    it('shows picker when tab has no terminalId and defaultNewPane is ask', () => {
+  describe('default content resolution', () => {
+    it('shows picker when defaultNewPane is ask', () => {
       const store = createStore([{ id: 'tab-1', mode: 'shell' }], { defaultNewPane: 'ask' })
 
       render(
@@ -124,7 +103,7 @@ describe('TabContent', () => {
       )
     })
 
-    it('passes undefined terminalId when tab has no terminalId and defaultNewPane is shell', () => {
+    it('passes terminal content when defaultNewPane is shell', () => {
       const store = createStore([{ id: 'tab-1', mode: 'shell' }], { defaultNewPane: 'shell' })
 
       render(
@@ -137,7 +116,7 @@ describe('TabContent', () => {
         expect.objectContaining({
           defaultContent: expect.objectContaining({
             kind: 'terminal',
-            terminalId: undefined,
+            mode: 'shell',
           }),
         }),
         expect.anything()
@@ -196,7 +175,7 @@ describe('TabContent', () => {
 
   describe('hidden prop propagation', () => {
     it('passes hidden=true to PaneLayout when hidden prop is true', () => {
-      const store = createStore([{ id: 'tab-1', mode: 'shell', terminalId: 'term-1' }])
+      const store = createStore([{ id: 'tab-1', mode: 'shell' }])
 
       render(
         <Provider store={store}>
@@ -211,7 +190,7 @@ describe('TabContent', () => {
     })
 
     it('passes hidden=false to PaneLayout when hidden prop is false', () => {
-      const store = createStore([{ id: 'tab-1', mode: 'shell', terminalId: 'term-1' }])
+      const store = createStore([{ id: 'tab-1', mode: 'shell' }])
 
       render(
         <Provider store={store}>
@@ -226,7 +205,7 @@ describe('TabContent', () => {
     })
 
     it('passes hidden=undefined to PaneLayout when hidden prop is not provided', () => {
-      const store = createStore([{ id: 'tab-1', mode: 'shell', terminalId: 'term-1' }])
+      const store = createStore([{ id: 'tab-1', mode: 'shell' }])
 
       render(
         <Provider store={store}>
@@ -243,7 +222,7 @@ describe('TabContent', () => {
 
   describe('visibility CSS classes', () => {
     it('applies tab-hidden class when hidden=true', () => {
-      const store = createStore([{ id: 'tab-1', mode: 'shell', terminalId: 'term-1' }])
+      const store = createStore([{ id: 'tab-1', mode: 'shell' }])
 
       const { container } = render(
         <Provider store={store}>
@@ -258,7 +237,7 @@ describe('TabContent', () => {
     })
 
     it('applies tab-visible class when hidden=false', () => {
-      const store = createStore([{ id: 'tab-1', mode: 'shell', terminalId: 'term-1' }])
+      const store = createStore([{ id: 'tab-1', mode: 'shell' }])
 
       const { container } = render(
         <Provider store={store}>
@@ -272,7 +251,7 @@ describe('TabContent', () => {
     })
 
     it('applies tab-visible class when hidden is undefined', () => {
-      const store = createStore([{ id: 'tab-1', mode: 'shell', terminalId: 'term-1' }])
+      const store = createStore([{ id: 'tab-1', mode: 'shell' }])
 
       const { container } = render(
         <Provider store={store}>
diff --git a/test/unit/client/components/TerminalView.lifecycle.test.tsx b/test/unit/client/components/TerminalView.lifecycle.test.tsx
index 359998c5..deda7c07 100644
--- a/test/unit/client/components/TerminalView.lifecycle.test.tsx
+++ b/test/unit/client/components/TerminalView.lifecycle.test.tsx
@@ -2257,7 +2257,6 @@ describe('TerminalView lifecycle updates', () => {
             status: 'running',
             title: 'Claude',
             titleSetByUser: false,
-            terminalId: 'term-clear',
             createRequestId: 'req-clear',
           }],
           activeTabId: tabId,
@@ -2290,10 +2289,10 @@ describe('TerminalView lifecycle updates', () => {
       terminalId: 'term-clear',
     })
 
-    // Wait for state update
+    // Wait for state update - pane content terminalId should be cleared
     await waitFor(() => {
-      const tab = store.getState().tabs.tabs.find(t => t.id === tabId)
-      expect(tab?.terminalId).toBeUndefined()
+      const layout = store.getState().panes.layouts[tabId] as { type: 'leaf'; content: any }
+      expect(layout.content.terminalId).toBeUndefined()
     })
 
     // Verify tab status was set to 'creating'
diff --git a/test/unit/client/lib/codex-activity-resolver.test.ts b/test/unit/client/lib/codex-activity-resolver.test.ts
index a1df431d..24494275 100644
--- a/test/unit/client/lib/codex-activity-resolver.test.ts
+++ b/test/unit/client/lib/codex-activity-resolver.test.ts
@@ -17,32 +17,23 @@ describe('resolveExactCodexActivity', () => {
 
     expect(resolveExactCodexActivity(
       { 'term-1': record },
-      { terminalId: 'term-1', tabTerminalId: 'term-tab', isOnlyPane: true },
+      { terminalId: 'term-1', isOnlyPane: true },
     )).toEqual(record)
   })
 
-  it('falls back to the exact tab terminal id only for a single-pane tab', () => {
+  it('returns undefined when pane has no terminalId even for single-pane tab', () => {
     const record = makeRecord({ terminalId: 'term-tab' })
 
     expect(resolveExactCodexActivity(
       { 'term-tab': record },
-      { terminalId: undefined, tabTerminalId: 'term-tab', isOnlyPane: true },
-    )).toEqual(record)
-  })
-
-  it('does not use the tab terminal id fallback for multi-pane tabs', () => {
-    const record = makeRecord({ terminalId: 'term-tab' })
-
-    expect(resolveExactCodexActivity(
-      { 'term-tab': record },
-      { terminalId: undefined, tabTerminalId: 'term-tab', isOnlyPane: false },
+      { terminalId: undefined, isOnlyPane: true },
     )).toBeUndefined()
   })
 
   it('returns undefined when there is no exact terminal id match', () => {
     expect(resolveExactCodexActivity(
       { 'term-other': makeRecord({ terminalId: 'term-other' }) },
-      { terminalId: undefined, tabTerminalId: undefined, isOnlyPane: true },
+      { terminalId: undefined, isOnlyPane: true },
     )).toBeUndefined()
   })
 })
diff --git a/test/unit/client/lib/session-type-utils.test.ts b/test/unit/client/lib/session-type-utils.test.ts
index ec0bcd1d..0a6ac3ad 100644
--- a/test/unit/client/lib/session-type-utils.test.ts
+++ b/test/unit/client/lib/session-type-utils.test.ts
@@ -94,19 +94,7 @@ describe('buildResumeContent', () => {
     expect(content.mode).toBe('claude')
   })
 
-  it('passes terminalId through for terminal panes', () => {
-    const content = buildResumeContent({
-      sessionType: 'claude',
-      sessionId: 'abc-123',
-      terminalId: 'term-42',
-    })
-    expect(content.kind).toBe('terminal')
-    if (content.kind !== 'terminal') throw new Error('expected terminal')
-    expect(content.terminalId).toBe('term-42')
-    expect(content.status).toBe('running')
-  })
-
-  it('sets status to creating when no terminalId', () => {
+  it('returns terminal content without terminalId (set at pane level)', () => {
     const content = buildResumeContent({
       sessionType: 'claude',
       sessionId: 'abc-123',
@@ -114,17 +102,16 @@ describe('buildResumeContent', () => {
     expect(content.kind).toBe('terminal')
     if (content.kind !== 'terminal') throw new Error('expected terminal')
     expect(content.terminalId).toBeUndefined()
-    expect(content.status).toBe('creating')
+    expect(content.mode).toBe('claude')
+    expect(content.resumeSessionId).toBe('abc-123')
   })
 
-  it('ignores terminalId for agent-chat panes', () => {
+  it('agent-chat panes have no terminalId', () => {
     const content = buildResumeContent({
       sessionType: 'freshclaude',
       sessionId: 'abc-123',
-      terminalId: 'term-42',
     })
     expect(content.kind).toBe('agent-chat')
-    // Agent-chat panes don't have terminalId
     expect('terminalId' in content).toBe(false)
   })
 
diff --git a/test/unit/client/store/atomicPersistence.test.ts b/test/unit/client/store/atomicPersistence.test.ts
new file mode 100644
index 00000000..041654bd
--- /dev/null
+++ b/test/unit/client/store/atomicPersistence.test.ts
@@ -0,0 +1,114 @@
+// Tests for atomic tabs+panes persistence via freshell.layout.v3
+import { describe, it, expect, beforeEach, vi } from 'vitest'
+import { LAYOUT_STORAGE_KEY, TABS_STORAGE_KEY, PANES_STORAGE_KEY } from '@/store/storage-keys'
+import { parsePersistedLayoutRaw, migrateV2ToV3 } from '@/store/persistedState'
+
+describe('atomic persistence', () => {
+  beforeEach(() => {
+    localStorage.clear()
+  })
+
+  describe('LAYOUT_STORAGE_KEY', () => {
+    it('is freshell.layout.v3', () => {
+      expect(LAYOUT_STORAGE_KEY).toBe('freshell.layout.v3')
+    })
+  })
+
+  describe('parsePersistedLayoutRaw', () => {
+    it('parses a valid v3 layout payload', () => {
+      const payload = {
+        version: 3,
+        tabs: {
+          activeTabId: 'tab-1',
+          tabs: [{ id: 'tab-1', title: 'Tab 1', status: 'running', mode: 'shell', createdAt: 1000 }],
+        },
+        panes: {
+          layouts: { 'tab-1': { type: 'leaf', id: 'pane-1', content: { kind: 'terminal', mode: 'shell' } } },
+          activePane: { 'tab-1': 'pane-1' },
+          paneTitles: {},
+          paneTitleSetByUser: {},
+        },
+        tombstones: [{ id: 'deleted-tab', deletedAt: 1000 }],
+      }
+
+      const result = parsePersistedLayoutRaw(JSON.stringify(payload))
+      expect(result).not.toBeNull()
+      expect(result!.tabs.tabs).toHaveLength(1)
+      expect(result!.tabs.tabs[0].id).toBe('tab-1')
+      expect(result!.panes.layouts).toHaveProperty('tab-1')
+      expect(result!.tombstones).toHaveLength(1)
+      expect(result!.tombstones[0].id).toBe('deleted-tab')
+    })
+
+    it('returns null for invalid JSON', () => {
+      expect(parsePersistedLayoutRaw('not json')).toBeNull()
+    })
+
+    it('returns null for missing tabs', () => {
+      expect(parsePersistedLayoutRaw(JSON.stringify({ version: 3, panes: {} }))).toBeNull()
+    })
+
+    it('defaults tombstones to empty array', () => {
+      const payload = {
+        version: 3,
+        tabs: { activeTabId: null, tabs: [] },
+        panes: { layouts: {}, activePane: {}, paneTitles: {}, paneTitleSetByUser: {} },
+      }
+      const result = parsePersistedLayoutRaw(JSON.stringify(payload))
+      expect(result!.tombstones).toEqual([])
+    })
+  })
+
+  describe('migrateV2ToV3', () => {
+    it('combines v2 tabs and panes into v3 layout', () => {
+      const v2Tabs = JSON.stringify({
+        tabs: {
+          activeTabId: 'tab-1',
+          tabs: [{ id: 'tab-1', title: 'Shell', status: 'running', mode: 'shell', createdAt: 1000 }],
+        },
+        tombstones: [{ id: 'old-tab', deletedAt: 500 }],
+      })
+      const v2Panes = JSON.stringify({
+        version: 6,
+        layouts: { 'tab-1': { type: 'leaf', id: 'pane-1', content: { kind: 'terminal', mode: 'shell' } } },
+        activePane: { 'tab-1': 'pane-1' },
+        paneTitles: {},
+        paneTitleSetByUser: {},
+      })
+
+      localStorage.setItem(TABS_STORAGE_KEY, v2Tabs)
+      localStorage.setItem(PANES_STORAGE_KEY, v2Panes)
+
+      const result = migrateV2ToV3()
+      expect(result).not.toBeNull()
+
+      // Should have written the v3 key
+      const v3Raw = localStorage.getItem(LAYOUT_STORAGE_KEY)
+      expect(v3Raw).not.toBeNull()
+
+      const v3 = JSON.parse(v3Raw!)
+      expect(v3.version).toBe(3)
+      expect(v3.tabs.tabs).toHaveLength(1)
+      expect(v3.panes.layouts).toHaveProperty('tab-1')
+      expect(v3.tombstones).toHaveLength(1)
+
+      // Should have deleted v2 keys
+      expect(localStorage.getItem(TABS_STORAGE_KEY)).toBeNull()
+      expect(localStorage.getItem(PANES_STORAGE_KEY)).toBeNull()
+    })
+
+    it('returns null when no v2 keys exist', () => {
+      expect(migrateV2ToV3()).toBeNull()
+    })
+
+    it('handles missing panes key — creates empty panes', () => {
+      localStorage.setItem(TABS_STORAGE_KEY, JSON.stringify({
+        tabs: { activeTabId: null, tabs: [] },
+      }))
+
+      const result = migrateV2ToV3()
+      expect(result).not.toBeNull()
+      expect(result!.panes.layouts).toEqual({})
+    })
+  })
+})
diff --git a/test/unit/client/store/crossTabSync.test.ts b/test/unit/client/store/crossTabSync.test.ts
index a08ac34d..9760e7f5 100644
--- a/test/unit/client/store/crossTabSync.test.ts
+++ b/test/unit/client/store/crossTabSync.test.ts
@@ -12,7 +12,7 @@ import {
   resetBrowserPreferencesFlushListenersForTests,
 } from '../../../../src/store/browserPreferencesPersistence'
 import { broadcastPersistedRaw, resetPersistBroadcastForTests } from '../../../../src/store/persistBroadcast'
-import { BROWSER_PREFERENCES_STORAGE_KEY, PANES_STORAGE_KEY, TABS_STORAGE_KEY } from '../../../../src/store/storage-keys'
+import { BROWSER_PREFERENCES_STORAGE_KEY, LAYOUT_STORAGE_KEY } from '../../../../src/store/storage-keys'
 import { resolveLocalSettings } from '@shared/settings'
 
 describe('crossTabSync', () => {
@@ -43,7 +43,7 @@ describe('crossTabSync', () => {
     cleanups.push(installCrossTabSync(store as any))
 
     const remoteRaw = JSON.stringify({
-      version: 1,
+      version: 3,
       tabs: {
         activeTabId: 't2',
         tabs: [
@@ -52,9 +52,11 @@ describe('crossTabSync', () => {
           { id: 't3', title: 'T3', createdAt: 3 },
         ],
       },
+      panes: { version: 6, layouts: {}, activePane: {}, paneTitles: {}, paneTitleSetByUser: {} },
+      tombstones: [],
     })
 
-    window.dispatchEvent(new StorageEvent('storage', { key: TABS_STORAGE_KEY, newValue: remoteRaw }))
+    window.dispatchEvent(new StorageEvent('storage', { key: LAYOUT_STORAGE_KEY, newValue: remoteRaw }))
 
     expect(store.getState().tabs.tabs.map((t) => t.id)).toEqual(['t1', 't2', 't3'])
     expect(store.getState().tabs.activeTabId).toBe('t1')
@@ -86,25 +88,29 @@ describe('crossTabSync', () => {
     cleanups.push(installCrossTabSync(store as any))
 
     const remoteRaw = JSON.stringify({
-      version: 4,
-      layouts: {
-        'tab-1': {
-          type: 'split',
-          id: 'split-remote',
-          direction: 'horizontal',
-          sizes: [50, 50],
-          children: [
-            { type: 'leaf', id: 'pane-a', content: { kind: 'terminal', mode: 'shell', createRequestId: 'req-a', status: 'running' } },
-            { type: 'leaf', id: 'pane-b', content: { kind: 'browser', url: 'https://example.com', devToolsOpen: false } },
-          ],
+      version: 3,
+      tabs: { activeTabId: null, tabs: [] },
+      panes: {
+        version: 6,
+        layouts: {
+          'tab-1': {
+            type: 'split',
+            id: 'split-remote',
+            direction: 'horizontal',
+            sizes: [50, 50],
+            children: [
+              { type: 'leaf', id: 'pane-a', content: { kind: 'terminal', mode: 'shell', createRequestId: 'req-a', status: 'running' } },
+              { type: 'leaf', id: 'pane-b', content: { kind: 'browser', url: 'https://example.com', devToolsOpen: false } },
+            ],
+          },
         },
+        activePane: { 'tab-1': 'pane-b' },
+        paneTitles: {},
       },
-      activePane: { 'tab-1': 'pane-b' },
-      paneTitles: {},
-
+      tombstones: [],
     })
 
-    window.dispatchEvent(new StorageEvent('storage', { key: PANES_STORAGE_KEY, newValue: remoteRaw }))
+    window.dispatchEvent(new StorageEvent('storage', { key: LAYOUT_STORAGE_KEY, newValue: remoteRaw }))
 
     expect(store.getState().panes.layouts['tab-1']?.id).toBe('split-remote')
     expect(store.getState().panes.activePane['tab-1']).toBe('pane-a')
@@ -132,12 +138,14 @@ describe('crossTabSync', () => {
       const cleanup = installCrossTabSync(storeLike as any)
 
       const raw = JSON.stringify({
-        version: 1,
+        version: 3,
         tabs: { activeTabId: null, tabs: [{ id: 't1', title: 'T1', createdAt: 1 }] },
+        panes: { version: 6, layouts: {}, activePane: {}, paneTitles: {}, paneTitleSetByUser: {} },
+        tombstones: [],
       })
-      window.dispatchEvent(new StorageEvent('storage', { key: TABS_STORAGE_KEY, newValue: raw }))
+      window.dispatchEvent(new StorageEvent('storage', { key: LAYOUT_STORAGE_KEY, newValue: raw }))
 
-      MockBC.instance!.onmessage?.({ data: { type: 'persist', key: TABS_STORAGE_KEY, raw, sourceId: 'other' } })
+      MockBC.instance!.onmessage?.({ data: { type: 'persist', key: LAYOUT_STORAGE_KEY, raw, sourceId: 'other' } })
 
       const hydrateCalls = dispatchSpy.mock.calls
         .map((c) => c[0])
@@ -446,28 +454,32 @@ describe('crossTabSync', () => {
 
     // Remote state arrives WITHOUT terminalId (stale data from before creation)
     const remoteRaw = JSON.stringify({
-      version: 4,
-      layouts: {
-        'tab-1': {
-          type: 'leaf',
-          id: 'pane-1',
-          content: {
-            kind: 'terminal',
-            mode: 'shell',
-            createRequestId: 'req-1',
-            status: 'creating',
-            // NO terminalId
+      version: 3,
+      tabs: { activeTabId: null, tabs: [] },
+      panes: {
+        version: 6,
+        layouts: {
+          'tab-1': {
+            type: 'leaf',
+            id: 'pane-1',
+            content: {
+              kind: 'terminal',
+              mode: 'shell',
+              createRequestId: 'req-1',
+              status: 'creating',
+              // NO terminalId
+            },
           },
         },
+        activePane: { 'tab-1': 'pane-1' },
+        paneTitles: { 'tab-1': { 'pane-1': 'Remote broken title' } },
+        paneTitleSetByUser: { 'tab-1': { 'pane-1': false } },
       },
-      activePane: { 'tab-1': 'pane-1' },
-      paneTitles: { 'tab-1': { 'pane-1': 'Remote broken title' } },
-      paneTitleSetByUser: { 'tab-1': { 'pane-1': false } },
-
+      tombstones: [],
     })
 
     cleanups.push(installCrossTabSync(store as any))
-    window.dispatchEvent(new StorageEvent('storage', { key: PANES_STORAGE_KEY, newValue: remoteRaw }))
+    window.dispatchEvent(new StorageEvent('storage', { key: LAYOUT_STORAGE_KEY, newValue: remoteRaw }))
 
     // Local terminalId should be preserved
     const content = (store.getState().panes.layouts['tab-1'] as any).content
@@ -502,28 +514,32 @@ describe('crossTabSync', () => {
 
     // Remote: stale state with old createRequestId and old terminalId
     const remoteRaw = JSON.stringify({
-      version: 4,
-      layouts: {
-        'tab-1': {
-          type: 'leaf',
-          id: 'pane-1',
-          content: {
-            kind: 'terminal',
-            mode: 'shell',
-            createRequestId: 'req-old',
-            status: 'running',
-            terminalId: 'stale-terminal-id',
+      version: 3,
+      tabs: { activeTabId: null, tabs: [] },
+      panes: {
+        version: 6,
+        layouts: {
+          'tab-1': {
+            type: 'leaf',
+            id: 'pane-1',
+            content: {
+              kind: 'terminal',
+              mode: 'shell',
+              createRequestId: 'req-old',
+              status: 'running',
+              terminalId: 'stale-terminal-id',
+            },
           },
         },
+        activePane: { 'tab-1': 'pane-1' },
+        paneTitles: { 'tab-1': { 'pane-1': 'Remote broken title' } },
+        paneTitleSetByUser: { 'tab-1': { 'pane-1': false } },
       },
-      activePane: { 'tab-1': 'pane-1' },
-      paneTitles: { 'tab-1': { 'pane-1': 'Remote broken title' } },
-      paneTitleSetByUser: { 'tab-1': { 'pane-1': false } },
-
+      tombstones: [],
     })
 
     cleanups.push(installCrossTabSync(store as any))
-    window.dispatchEvent(new StorageEvent('storage', { key: PANES_STORAGE_KEY, newValue: remoteRaw }))
+    window.dispatchEvent(new StorageEvent('storage', { key: LAYOUT_STORAGE_KEY, newValue: remoteRaw }))
 
     // Local reconnection state must be preserved — stale remote must not overwrite
     const content = (store.getState().panes.layouts['tab-1'] as any).content
@@ -558,27 +574,31 @@ describe('crossTabSync', () => {
 
     // Remote: terminal has exited (no terminalId, status: exited)
     const remoteRaw = JSON.stringify({
-      version: 4,
-      layouts: {
-        'tab-1': {
-          type: 'leaf',
-          id: 'pane-1',
-          content: {
-            kind: 'terminal',
-            mode: 'shell',
-            createRequestId: 'req-1',
-            status: 'exited',
-            // NO terminalId — terminal exited
+      version: 3,
+      tabs: { activeTabId: null, tabs: [] },
+      panes: {
+        version: 6,
+        layouts: {
+          'tab-1': {
+            type: 'leaf',
+            id: 'pane-1',
+            content: {
+              kind: 'terminal',
+              mode: 'shell',
+              createRequestId: 'req-1',
+              status: 'exited',
+              // NO terminalId — terminal exited
+            },
           },
         },
+        activePane: { 'tab-1': 'pane-1' },
+        paneTitles: {},
       },
-      activePane: { 'tab-1': 'pane-1' },
-      paneTitles: {},
-
+      tombstones: [],
     })
 
     cleanups.push(installCrossTabSync(store as any))
-    window.dispatchEvent(new StorageEvent('storage', { key: PANES_STORAGE_KEY, newValue: remoteRaw }))
+    window.dispatchEvent(new StorageEvent('storage', { key: LAYOUT_STORAGE_KEY, newValue: remoteRaw }))
 
     // Exit state should propagate — local should NOT keep stale terminalId
     const content = (store.getState().panes.layouts['tab-1'] as any).content
@@ -613,27 +633,31 @@ describe('crossTabSync', () => {
 
     // Remote state: malformed split with missing children
     const remoteRaw = JSON.stringify({
-      version: 4,
-      layouts: {
-        'tab-1': {
-          type: 'split',
-          id: 'split-bad',
-          direction: 'horizontal',
-          sizes: [50, 50],
-          // children is missing entirely — corrupted data
+      version: 3,
+      tabs: { activeTabId: null, tabs: [] },
+      panes: {
+        version: 6,
+        layouts: {
+          'tab-1': {
+            type: 'split',
+            id: 'split-bad',
+            direction: 'horizontal',
+            sizes: [50, 50],
+            // children is missing entirely — corrupted data
+          },
         },
+        activePane: { 'tab-1': 'pane-1' },
+        paneTitles: { 'tab-1': { 'pane-1': 'Remote broken title' } },
+        paneTitleSetByUser: { 'tab-1': { 'pane-1': false } },
       },
-      activePane: { 'tab-1': 'pane-1' },
-      paneTitles: { 'tab-1': { 'pane-1': 'Remote broken title' } },
-      paneTitleSetByUser: { 'tab-1': { 'pane-1': false } },
-
+      tombstones: [],
     })
 
     cleanups.push(installCrossTabSync(store as any))
 
     // Should not throw — malformed remote data is ignored and local state wins.
     expect(() => {
-      window.dispatchEvent(new StorageEvent('storage', { key: PANES_STORAGE_KEY, newValue: remoteRaw }))
+      window.dispatchEvent(new StorageEvent('storage', { key: LAYOUT_STORAGE_KEY, newValue: remoteRaw }))
     }).not.toThrow()
 
     expect(store.getState().panes.layouts['tab-1']).toEqual({
@@ -677,28 +701,32 @@ describe('crossTabSync', () => {
 
     // Remote: same createRequestId but different resumeSessionId (from another tab)
     const remoteRaw = JSON.stringify({
-      version: 4,
-      layouts: {
-        'tab-1': {
-          type: 'leaf',
-          id: 'pane-1',
-          content: {
-            kind: 'terminal',
-            mode: 'claude',
-            createRequestId: 'req-1',
-            status: 'running',
-            terminalId: 'remote-terminal-456',
-            resumeSessionId: 'session-B',
+      version: 3,
+      tabs: { activeTabId: null, tabs: [] },
+      panes: {
+        version: 6,
+        layouts: {
+          'tab-1': {
+            type: 'leaf',
+            id: 'pane-1',
+            content: {
+              kind: 'terminal',
+              mode: 'claude',
+              createRequestId: 'req-1',
+              status: 'running',
+              terminalId: 'remote-terminal-456',
+              resumeSessionId: 'session-B',
+            },
           },
         },
+        activePane: { 'tab-1': 'pane-1' },
+        paneTitles: {},
       },
-      activePane: { 'tab-1': 'pane-1' },
-      paneTitles: {},
-
+      tombstones: [],
     })
 
     cleanups.push(installCrossTabSync(store as any))
-    window.dispatchEvent(new StorageEvent('storage', { key: PANES_STORAGE_KEY, newValue: remoteRaw }))
+    window.dispatchEvent(new StorageEvent('storage', { key: LAYOUT_STORAGE_KEY, newValue: remoteRaw }))
 
     // Local resumeSessionId must NOT be overwritten by remote
     const content = (store.getState().panes.layouts['tab-1'] as any).content
@@ -718,18 +746,22 @@ describe('crossTabSync', () => {
     cleanups.push(installCrossTabSync(storeLike as any))
 
     const raw1 = JSON.stringify({
-      version: 1,
+      version: 3,
       tabs: { activeTabId: null, tabs: [{ id: 't1', title: 'T1', createdAt: 1 }] },
+      panes: { version: 6, layouts: {}, activePane: {}, paneTitles: {}, paneTitleSetByUser: {} },
+      tombstones: [],
     })
-    window.dispatchEvent(new StorageEvent('storage', { key: TABS_STORAGE_KEY, newValue: raw1 }))
+    window.dispatchEvent(new StorageEvent('storage', { key: LAYOUT_STORAGE_KEY, newValue: raw1 }))
 
     const raw2 = JSON.stringify({
-      version: 1,
+      version: 3,
       tabs: { activeTabId: null, tabs: [{ id: 't1', title: 'T1 local change', createdAt: 1 }] },
+      panes: { version: 6, layouts: {}, activePane: {}, paneTitles: {}, paneTitleSetByUser: {} },
+      tombstones: [],
     })
-    broadcastPersistedRaw(TABS_STORAGE_KEY, raw2)
+    broadcastPersistedRaw(LAYOUT_STORAGE_KEY, raw2)
 
-    window.dispatchEvent(new StorageEvent('storage', { key: TABS_STORAGE_KEY, newValue: raw1 }))
+    window.dispatchEvent(new StorageEvent('storage', { key: LAYOUT_STORAGE_KEY, newValue: raw1 }))
 
     const hydrateCalls = dispatchSpy.mock.calls
       .map((c) => c[0])
@@ -737,16 +769,15 @@ describe('crossTabSync', () => {
     expect(hydrateCalls).toHaveLength(2)
   })
 
-  it('hydrates paired panes when tabs event arrives first', () => {
+  it('hydrates both tabs and panes from a single combined layout event', () => {
     const store = configureStore({
       reducer: { tabs: tabsReducer, panes: panesReducer },
     })
 
-    // Install sync first (captures current empty localStorage as baseline)
     cleanups.push(installCrossTabSync(store as any))
 
-    const tabsRaw = JSON.stringify({
-      version: 1,
+    const layoutRaw = JSON.stringify({
+      version: 3,
       tabs: {
         activeTabId: 't1',
         tabs: [
@@ -754,26 +785,21 @@ describe('crossTabSync', () => {
           { id: 't2', title: 'T2', mode: 'shell' },
         ],
       },
-    })
-
-    const panesRaw = JSON.stringify({
-      version: 6,
-      layouts: {
-        't1': { type: 'leaf', id: 'p1', content: { kind: 'terminal', mode: 'shell', createRequestId: 'r1', status: 'running' } },
-        't2': { type: 'leaf', id: 'p2', content: { kind: 'terminal', mode: 'shell', createRequestId: 'r2', status: 'running' } },
+      panes: {
+        version: 6,
+        layouts: {
+          't1': { type: 'leaf', id: 'p1', content: { kind: 'terminal', mode: 'shell', createRequestId: 'r1', status: 'running' } },
+          't2': { type: 'leaf', id: 'p2', content: { kind: 'terminal', mode: 'shell', createRequestId: 'r2', status: 'running' } },
+        },
+        activePane: { 't1': 'p1', 't2': 'p2' },
+        paneTitles: {},
       },
-      activePane: { 't1': 'p1', 't2': 'p2' },
-      paneTitles: {},
+      tombstones: [],
     })
 
-    // Simulate flush() in another tab: both are written to localStorage
-    localStorage.setItem(TABS_STORAGE_KEY, tabsRaw)
-    localStorage.setItem(PANES_STORAGE_KEY, panesRaw)
-
-    // Only the tabs event arrives — panes should also be hydrated from localStorage
-    window.dispatchEvent(new StorageEvent('storage', { key: TABS_STORAGE_KEY, newValue: tabsRaw }))
+    window.dispatchEvent(new StorageEvent('storage', { key: LAYOUT_STORAGE_KEY, newValue: layoutRaw }))
 
-    // Both tabs and panes should be hydrated consistently
+    // Both tabs and panes should be hydrated from the single combined event
     expect(store.getState().tabs.tabs.map((t: any) => t.id)).toEqual(['t1', 't2'])
     expect(store.getState().panes.layouts).toHaveProperty('t1')
     expect(store.getState().panes.layouts).toHaveProperty('t2')
diff --git a/test/unit/client/store/panesPersistence.test.ts b/test/unit/client/store/panesPersistence.test.ts
index 5d7780c6..d33ec6ad 100644
--- a/test/unit/client/store/panesPersistence.test.ts
+++ b/test/unit/client/store/panesPersistence.test.ts
@@ -25,6 +25,7 @@ import {
   persistMiddleware,
   resetPersistFlushListenersForTests,
   resetPersistedPanesCacheForTests,
+  resetPersistedLayoutCacheForTests,
 } from '../../../../src/store/persistMiddleware'
 import { PANES_SCHEMA_VERSION } from '../../../../src/store/persistedState'
 
@@ -35,6 +36,7 @@ describe('Panes Persistence Integration', () => {
     vi.useFakeTimers()
     resetPersistFlushListenersForTests()
     resetPersistedPanesCacheForTests()
+    resetPersistedLayoutCacheForTests()
   })
 
   afterEach(() => {
@@ -74,10 +76,10 @@ describe('Panes Persistence Integration', () => {
 
     // 6. Check localStorage was updated
     vi.runAllTimers()
-    const savedPanes = localStorage.getItem('freshell.panes.v2')
-    expect(savedPanes).not.toBeNull()
-    const parsedPanes = JSON.parse(savedPanes!)
-    expect(parsedPanes.layouts[tabId].type).toBe('split')
+    const savedLayout = localStorage.getItem('freshell.layout.v3')
+    expect(savedLayout).not.toBeNull()
+    const parsedLayout = JSON.parse(savedLayout!)
+    expect(parsedLayout.panes.layouts[tabId].type).toBe('split')
 
     // 7. Simulate page refresh - create new store and hydrate
     // (Using explicit hydration to test that path still works)
@@ -191,9 +193,9 @@ describe('Panes Persistence Integration', () => {
 
     // Verify state was persisted
     vi.runAllTimers()
-    const savedPanes = localStorage.getItem('freshell.panes.v2')
-    expect(savedPanes).not.toBeNull()
-    expect(JSON.parse(savedPanes!).layouts[tabId].type).toBe('split')
+    const savedLayout = localStorage.getItem('freshell.layout.v3')
+    expect(savedLayout).not.toBeNull()
+    expect(JSON.parse(savedLayout!).panes.layouts[tabId].type).toBe('split')
 
     // 2. Verify loadPersistedPanes returns correct data
     const loaded = loadPersistedPanes()
@@ -228,10 +230,10 @@ describe('Panes Persistence Integration', () => {
 
     vi.runAllTimers()
 
-    const savedPanes = localStorage.getItem('freshell.panes.v2')
-    expect(savedPanes).not.toBeNull()
-    const parsedPanes = JSON.parse(savedPanes!)
-    const layout = parsedPanes.layouts[tabId]
+    const savedLayout = localStorage.getItem('freshell.layout.v3')
+    expect(savedLayout).not.toBeNull()
+    const parsedLayout = JSON.parse(savedLayout!)
+    const layout = parsedLayout.panes.layouts[tabId]
     expect(layout.content.kind).toBe('editor')
     expect(layout.content.content).toBe('')
   })
@@ -353,8 +355,8 @@ describe('Panes Persistence Integration', () => {
 
     vi.runAllTimers()
 
-    const saved = JSON.parse(localStorage.getItem('freshell.panes.v2')!)
-    expect(saved.refreshRequestsByPane).toBeUndefined()
+    const saved = JSON.parse(localStorage.getItem('freshell.layout.v3')!)
+    expect(saved.panes.refreshRequestsByPane).toBeUndefined()
   })
 
   it('flushes pending writes on visibility change', () => {
@@ -370,12 +372,12 @@ describe('Panes Persistence Integration', () => {
     const tabId = store.getState().tabs.tabs[0].id
     store.dispatch(initLayout({ tabId, content: { kind: 'terminal', mode: 'shell' } }))
 
-    expect(localStorage.getItem('freshell.panes.v2')).toBeNull()
+    expect(localStorage.getItem('freshell.layout.v3')).toBeNull()
 
     Object.defineProperty(document, 'visibilityState', { value: 'hidden', configurable: true })
     document.dispatchEvent(new Event('visibilitychange'))
 
-    expect(localStorage.getItem('freshell.panes.v2')).not.toBeNull()
+    expect(localStorage.getItem('freshell.layout.v3')).not.toBeNull()
   })
 })
 
@@ -383,6 +385,7 @@ describe('PaneContent migration', () => {
   beforeEach(() => {
     localStorageMock.clear()
     resetPersistedPanesCacheForTests()
+    resetPersistedLayoutCacheForTests()
   })
 
   it('migrates old terminal pane content to include lifecycle fields', () => {
@@ -542,6 +545,7 @@ describe('version 3 migration', () => {
   beforeEach(() => {
     localStorageMock.clear()
     resetPersistedPanesCacheForTests()
+    resetPersistedLayoutCacheForTests()
   })
 
   it('adds empty paneTitles when migrating from version 2', () => {
@@ -578,6 +582,7 @@ describe('loadInitialPanesState consistency', () => {
   beforeEach(() => {
     localStorageMock.clear()
     resetPersistedPanesCacheForTests()
+    resetPersistedLayoutCacheForTests()
   })
 
   it('initial pane state matches loadPersistedPanes output for migrated data', async () => {
@@ -618,6 +623,7 @@ describe('orphaned layout cleanup', () => {
   beforeEach(() => {
     localStorageMock.clear()
     resetPersistedPanesCacheForTests()
+    resetPersistedLayoutCacheForTests()
   })
 
   it('removes pane layouts for tabs that no longer exist', async () => {
@@ -660,6 +666,7 @@ describe('version 5 migration (drop claude-chat panes)', () => {
   beforeEach(() => {
     localStorageMock.clear()
     resetPersistedPanesCacheForTests()
+    resetPersistedLayoutCacheForTests()
   })
 
   it('drops claude-chat leaf panes during v4→v5 migration', () => {
@@ -743,6 +750,7 @@ describe('schema version consistency', () => {
     vi.useFakeTimers()
     resetPersistFlushListenersForTests()
     resetPersistedPanesCacheForTests()
+    resetPersistedLayoutCacheForTests()
   })
 
   afterEach(() => {
@@ -760,9 +768,9 @@ describe('schema version consistency', () => {
     store.dispatch(initLayout({ tabId, content: { kind: 'terminal', mode: 'shell' } }))
     vi.runAllTimers()
 
-    const raw = localStorage.getItem('freshell.panes.v2')!
+    const raw = localStorage.getItem('freshell.layout.v3')!
     const parsed = JSON.parse(raw)
     // The version written by persist middleware must match persistedState's version
-    expect(parsed.version).toBe(PANES_SCHEMA_VERSION)
+    expect(parsed.panes.version).toBe(PANES_SCHEMA_VERSION)
   })
 })
diff --git a/test/unit/client/store/selectors/paneTerminalSelectors.test.ts b/test/unit/client/store/selectors/paneTerminalSelectors.test.ts
new file mode 100644
index 00000000..f5cc2450
--- /dev/null
+++ b/test/unit/client/store/selectors/paneTerminalSelectors.test.ts
@@ -0,0 +1,199 @@
+// Tests for pane-tree terminal ID selectors that replace Tab.terminalId reads.
+
+import { describe, it, expect } from 'vitest'
+import type { PaneNode } from '@/store/paneTypes'
+import {
+  selectTerminalIdsForTab,
+  selectPrimaryTerminalIdForTab,
+  selectTabIdByTerminalId,
+} from '@/store/selectors/paneTerminalSelectors'
+
+function makeLeaf(id: string, terminalId?: string): PaneNode {
+  return {
+    type: 'leaf',
+    id,
+    content: {
+      kind: 'terminal',
+      terminalId,
+      createRequestId: `req-${id}`,
+      status: 'running',
+      mode: 'shell',
+    },
+  }
+}
+
+function makeBrowserLeaf(id: string): PaneNode {
+  return {
+    type: 'leaf',
+    id,
+    content: {
+      kind: 'browser',
+      browserInstanceId: `bi-${id}`,
+      url: 'https://example.com',
+      devToolsOpen: false,
+    },
+  }
+}
+
+function makeSplit(left: PaneNode, right: PaneNode): PaneNode {
+  return {
+    type: 'split',
+    id: 'split-1',
+    direction: 'horizontal',
+    children: [left, right],
+    sizes: [50, 50],
+  }
+}
+
+function makeState(overrides: {
+  layouts?: Record<string, PaneNode>
+  activePane?: Record<string, string>
+}) {
+  return {
+    panes: {
+      layouts: overrides.layouts ?? {},
+      activePane: overrides.activePane ?? {},
+      paneTitles: {},
+      paneTitleSetByUser: {},
+      renameRequestTabId: null,
+      renameRequestPaneId: null,
+      zoomedPane: {},
+      refreshRequestsByPane: {},
+    },
+  } as any
+}
+
+describe('selectTerminalIdsForTab', () => {
+  it('returns empty array when no layout exists', () => {
+    const state = makeState({})
+    expect(selectTerminalIdsForTab(state, 'tab-1')).toEqual([])
+  })
+
+  it('returns single terminal ID from a leaf', () => {
+    const state = makeState({
+      layouts: { 'tab-1': makeLeaf('pane-1', 'term-abc') },
+    })
+    expect(selectTerminalIdsForTab(state, 'tab-1')).toEqual(['term-abc'])
+  })
+
+  it('skips leaves without terminal IDs', () => {
+    const state = makeState({
+      layouts: { 'tab-1': makeLeaf('pane-1') },
+    })
+    expect(selectTerminalIdsForTab(state, 'tab-1')).toEqual([])
+  })
+
+  it('collects terminal IDs from split layout', () => {
+    const state = makeState({
+      layouts: {
+        'tab-1': makeSplit(
+          makeLeaf('pane-1', 'term-a'),
+          makeLeaf('pane-2', 'term-b'),
+        ),
+      },
+    })
+    expect(selectTerminalIdsForTab(state, 'tab-1')).toEqual(['term-a', 'term-b'])
+  })
+
+  it('ignores non-terminal panes in split', () => {
+    const state = makeState({
+      layouts: {
+        'tab-1': makeSplit(
+          makeLeaf('pane-1', 'term-a'),
+          makeBrowserLeaf('pane-2'),
+        ),
+      },
+    })
+    expect(selectTerminalIdsForTab(state, 'tab-1')).toEqual(['term-a'])
+  })
+})
+
+describe('selectPrimaryTerminalIdForTab', () => {
+  it('returns undefined when no layout exists', () => {
+    const state = makeState({})
+    expect(selectPrimaryTerminalIdForTab(state, 'tab-1')).toBeUndefined()
+  })
+
+  it('returns the active pane terminal ID when available', () => {
+    const state = makeState({
+      layouts: {
+        'tab-1': makeSplit(
+          makeLeaf('pane-1', 'term-a'),
+          makeLeaf('pane-2', 'term-b'),
+        ),
+      },
+      activePane: { 'tab-1': 'pane-2' },
+    })
+    expect(selectPrimaryTerminalIdForTab(state, 'tab-1')).toBe('term-b')
+  })
+
+  it('falls back to first leaf when active pane has no terminal ID', () => {
+    const state = makeState({
+      layouts: {
+        'tab-1': makeSplit(
+          makeLeaf('pane-1', 'term-a'),
+          makeBrowserLeaf('pane-2'),
+        ),
+      },
+      activePane: { 'tab-1': 'pane-2' },
+    })
+    expect(selectPrimaryTerminalIdForTab(state, 'tab-1')).toBe('term-a')
+  })
+
+  it('falls back to first leaf when no active pane is set', () => {
+    const state = makeState({
+      layouts: { 'tab-1': makeLeaf('pane-1', 'term-a') },
+    })
+    expect(selectPrimaryTerminalIdForTab(state, 'tab-1')).toBe('term-a')
+  })
+
+  it('returns undefined when leaf has no terminal ID', () => {
+    const state = makeState({
+      layouts: { 'tab-1': makeLeaf('pane-1') },
+    })
+    expect(selectPrimaryTerminalIdForTab(state, 'tab-1')).toBeUndefined()
+  })
+})
+
+describe('selectTabIdByTerminalId', () => {
+  it('returns undefined when no tabs have layouts', () => {
+    const state = makeState({})
+    expect(selectTabIdByTerminalId(state, 'term-a')).toBeUndefined()
+  })
+
+  it('finds tab ID for a terminal in a leaf', () => {
+    const state = makeState({
+      layouts: { 'tab-1': makeLeaf('pane-1', 'term-a') },
+    })
+    expect(selectTabIdByTerminalId(state, 'term-a')).toBe('tab-1')
+  })
+
+  it('finds tab ID for a terminal in a split', () => {
+    const state = makeState({
+      layouts: {
+        'tab-1': makeSplit(
+          makeBrowserLeaf('pane-1'),
+          makeLeaf('pane-2', 'term-b'),
+        ),
+      },
+    })
+    expect(selectTabIdByTerminalId(state, 'term-b')).toBe('tab-1')
+  })
+
+  it('returns the correct tab when multiple tabs exist', () => {
+    const state = makeState({
+      layouts: {
+        'tab-1': makeLeaf('pane-1', 'term-a'),
+        'tab-2': makeLeaf('pane-2', 'term-b'),
+      },
+    })
+    expect(selectTabIdByTerminalId(state, 'term-b')).toBe('tab-2')
+  })
+
+  it('returns undefined for unknown terminal ID', () => {
+    const state = makeState({
+      layouts: { 'tab-1': makeLeaf('pane-1', 'term-a') },
+    })
+    expect(selectTabIdByTerminalId(state, 'term-unknown')).toBeUndefined()
+  })
+})
diff --git a/test/unit/client/store/sessionsSlice.test.ts b/test/unit/client/store/sessionsSlice.test.ts
index 43e68cd7..b94f70d2 100644
--- a/test/unit/client/store/sessionsSlice.test.ts
+++ b/test/unit/client/store/sessionsSlice.test.ts
@@ -8,8 +8,6 @@ import sessionsReducer, {
   applySessionsPatch,
   toggleProjectExpanded,
   setProjectExpanded,
-  collapseAll,
-  expandAll,
   SessionsState,
   setActiveSessionSurface,
   commitSessionWindowReplacement,
@@ -600,73 +598,6 @@ describe('sessionsSlice', () => {
     })
   })
 
-  describe('collapseAll', () => {
-    it('collapses all expanded projects', () => {
-      const stateWithExpanded = {
-        ...initialState,
-        expandedProjects: new Set(['/project/one', '/project/two', '/project/three']),
-      }
-      const state = sessionsReducer(stateWithExpanded, collapseAll())
-      expect(state.expandedProjects.size).toBe(0)
-    })
-
-    it('works when no projects are expanded', () => {
-      const state = sessionsReducer(initialState, collapseAll())
-      expect(state.expandedProjects.size).toBe(0)
-    })
-
-    it('preserves projects list', () => {
-      const stateWithProjects = {
-        ...initialState,
-        projects: mockProjects,
-        expandedProjects: new Set(['/project/one']),
-      }
-      const state = sessionsReducer(stateWithProjects, collapseAll())
-      expect(state.projects).toEqual(mockProjects)
-    })
-  })
-
-  describe('expandAll', () => {
-    it('expands all projects in the list', () => {
-      const stateWithProjects = {
-        ...initialState,
-        projects: mockProjects,
-        expandedProjects: new Set<string>(),
-      }
-      const state = sessionsReducer(stateWithProjects, expandAll())
-      expect(state.expandedProjects.size).toBe(3)
-      expect(state.expandedProjects.has('/project/one')).toBe(true)
-      expect(state.expandedProjects.has('/project/two')).toBe(true)
-      expect(state.expandedProjects.has('/project/three')).toBe(true)
-    })
-
-    it('works when some projects are already expanded', () => {
-      const stateWithProjects = {
-        ...initialState,
-        projects: mockProjects,
-        expandedProjects: new Set(['/project/one']),
-      }
-      const state = sessionsReducer(stateWithProjects, expandAll())
-      expect(state.expandedProjects.size).toBe(3)
-    })
-
-    it('replaces expandedProjects with new Set', () => {
-      const stateWithProjects = {
-        ...initialState,
-        projects: mockProjects,
-        expandedProjects: new Set(['/old/project']),
-      }
-      const state = sessionsReducer(stateWithProjects, expandAll())
-      expect(state.expandedProjects.has('/old/project')).toBe(false)
-      expect(state.expandedProjects.size).toBe(3)
-    })
-
-    it('handles empty projects list', () => {
-      const state = sessionsReducer(initialState, expandAll())
-      expect(state.expandedProjects.size).toBe(0)
-    })
-  })
-
   describe('state immutability', () => {
     it('does not mutate original state on setProjects', () => {
       const originalProjects = [...initialState.projects]
@@ -686,7 +617,7 @@ describe('sessionsSlice', () => {
   })
 
   describe('complex scenarios', () => {
-    it('handles workflow: load projects, expand some, collapse all, expand all', () => {
+    it('handles workflow: load projects, expand some, toggle back', () => {
       let state = sessionsReducer(initialState, setProjects(mockProjects))
       expect(state.projects.length).toBe(3)
 
@@ -694,16 +625,16 @@ describe('sessionsSlice', () => {
       state = sessionsReducer(state, toggleProjectExpanded('/project/two'))
       expect(state.expandedProjects.size).toBe(2)
 
-      state = sessionsReducer(state, collapseAll())
+      state = sessionsReducer(state, toggleProjectExpanded('/project/one'))
+      state = sessionsReducer(state, toggleProjectExpanded('/project/two'))
       expect(state.expandedProjects.size).toBe(0)
-
-      state = sessionsReducer(state, expandAll())
-      expect(state.expandedProjects.size).toBe(3)
     })
 
     it('handles replacing projects while some are expanded', () => {
       let state = sessionsReducer(initialState, setProjects(mockProjects))
-      state = sessionsReducer(state, expandAll())
+      state = sessionsReducer(state, toggleProjectExpanded('/project/one'))
+      state = sessionsReducer(state, toggleProjectExpanded('/project/two'))
+      state = sessionsReducer(state, toggleProjectExpanded('/project/three'))
       expect(state.expandedProjects.size).toBe(3)
 
       const newProjects: ProjectGroup[] = [
diff --git a/test/unit/client/store/state-edge-cases.test.ts b/test/unit/client/store/state-edge-cases.test.ts
index e047588a..d9447e31 100644
--- a/test/unit/client/store/state-edge-cases.test.ts
+++ b/test/unit/client/store/state-edge-cases.test.ts
@@ -25,8 +25,6 @@ import sessionsReducer, {
   setProjects,
   toggleProjectExpanded,
   setProjectExpanded,
-  collapseAll,
-  expandAll,
   SessionsState,
 } from '@/store/sessionsSlice'
 import connectionReducer, {
@@ -352,7 +350,7 @@ describe('State Edge Cases', () => {
         expect(store.getState().tabs.tabs).toHaveLength(0)
       })
 
-      it('handles hydrateTabs called multiple times', () => {
+      it('handles hydrateTabs called multiple times — set union', () => {
         const store = createTestStore()
 
         const firstHydration: Tab[] = [
@@ -366,11 +364,14 @@ describe('State Edge Cases', () => {
         store.dispatch(hydrateTabs({ tabs: firstHydration, activeTabId: 'first-1' }))
         store.dispatch(hydrateTabs({ tabs: secondHydration, activeTabId: 'second-2' }))
 
-        // Second hydration should completely replace first
+        // Set union: remote tabs (second-1, second-2) + local-only (first-1) appended
         const state = store.getState().tabs
-        expect(state.tabs).toHaveLength(2)
+        expect(state.tabs).toHaveLength(3)
         expect(state.tabs[0].id).toBe('second-1')
-        expect(state.activeTabId).toBe('second-2')
+        expect(state.tabs[1].id).toBe('second-2')
+        expect(state.tabs[2].id).toBe('first-1')
+        // Local activeTabId (first-1) still exists in merged set, so it's preserved
+        expect(state.activeTabId).toBe('first-1')
       })
     })
 
@@ -500,26 +501,6 @@ describe('State Edge Cases', () => {
         expect(store.getState().sessions.expandedProjects.has('/old/project')).toBe(false)
       })
 
-      it('handles expandAll when projects are empty', () => {
-        const store = createTestStore()
-
-        store.dispatch(expandAll())
-
-        expect(store.getState().sessions.expandedProjects.size).toBe(0)
-      })
-
-      it('handles collapseAll when nothing is expanded', () => {
-        const store = createTestStore()
-
-        const projects: ProjectGroup[] = [
-          { projectPath: '/project/a', sessions: [] },
-        ]
-        store.dispatch(setProjects(projects))
-        store.dispatch(collapseAll())
-
-        expect(store.getState().sessions.expandedProjects.size).toBe(0)
-      })
-
       it('handles rapid setProjects calls', () => {
         const store = createTestStore()
 
@@ -575,7 +556,7 @@ describe('State Edge Cases', () => {
           { projectPath: 'C:\\Windows\\Path', sessions: [] },
         ]
         store.dispatch(setProjects(projects))
-        store.dispatch(expandAll())
+        for (const p of projects) store.dispatch(toggleProjectExpanded(p.projectPath))
 
         const expanded = store.getState().sessions.expandedProjects
         expect(expanded.size).toBe(4)
diff --git a/test/unit/client/store/tabsPersistence.test.ts b/test/unit/client/store/tabsPersistence.test.ts
index 80d1a24e..01edad19 100644
--- a/test/unit/client/store/tabsPersistence.test.ts
+++ b/test/unit/client/store/tabsPersistence.test.ts
@@ -36,6 +36,7 @@ function makeStore() {
           lastInputAt: 111,
         }],
         activeTabId: 'tab-1',
+        tombstones: [],
       },
     },
   })
@@ -76,7 +77,7 @@ describe('tabs persistence - skipPersist + strip volatile fields', () => {
     store.dispatch(updateTab({ id: 'tab-1', updates: { lastInputAt: 999 } }))
     vi.runAllTimers()
 
-    const raw = localStorage.getItem('freshell.tabs.v2')
+    const raw = localStorage.getItem('freshell.layout.v3')
     expect(raw).not.toBeNull()
     const parsed = JSON.parse(raw!)
     expect(parsed.tabs.tabs[0].lastInputAt).toBeUndefined()
diff --git a/test/unit/client/store/tabsSlice.merge.test.ts b/test/unit/client/store/tabsSlice.merge.test.ts
new file mode 100644
index 00000000..9e964f08
--- /dev/null
+++ b/test/unit/client/store/tabsSlice.merge.test.ts
@@ -0,0 +1,264 @@
+// Tests for cross-tab tombstone merge in hydrateTabs
+import { describe, it, expect } from 'vitest'
+import tabsReducer, { addTab, hydrateTabs, removeTab, updateTab } from '@/store/tabsSlice'
+import type { Tab } from '@/store/types'
+import type { TabsState } from '@/store/tabsSlice'
+
+function makeTab(overrides: Partial<Tab> & { id: string }): Tab {
+  return {
+    createRequestId: overrides.id,
+    title: `Tab ${overrides.id}`,
+    status: 'running',
+    mode: 'shell',
+    shell: 'system',
+    createdAt: Date.now(),
+    updatedAt: Date.now(),
+    ...overrides,
+  }
+}
+
+function makeState(tabs: Tab[], activeTabId?: string | null, tombstones?: TabsState['tombstones']): TabsState {
+  return {
+    tabs,
+    activeTabId: activeTabId ?? tabs[0]?.id ?? null,
+    renameRequestTabId: null,
+    tombstones: tombstones ?? [],
+  }
+}
+
+describe('hydrateTabs merge', () => {
+  it('merges local and remote tabs as a set union', () => {
+    const shared = makeTab({ id: 'shared', title: 'Shared' })
+    const localOnly = makeTab({ id: 'local-only', title: 'Local Only' })
+    const remoteOnly = makeTab({ id: 'remote-only', title: 'Remote Only' })
+
+    const localState = makeState([shared, localOnly], 'shared')
+
+    const result = tabsReducer(
+      localState,
+      hydrateTabs({
+        tabs: [shared, remoteOnly],
+        activeTabId: 'shared',
+        renameRequestTabId: null,
+        tombstones: [],
+      })
+    )
+
+    const ids = result.tabs.map(t => t.id)
+    // All three should be present — union, not replacement
+    expect(ids).toContain('shared')
+    expect(ids).toContain('local-only')
+    expect(ids).toContain('remote-only')
+    expect(result.tabs).toHaveLength(3)
+  })
+
+  it('does not resurrect tombstoned tabs from remote', () => {
+    const localTab = makeTab({ id: 'alive', title: 'Alive' })
+    const deletedTab = makeTab({ id: 'deleted', title: 'Deleted' })
+
+    const localState = makeState(
+      [localTab],
+      'alive',
+      [{ id: 'deleted', deletedAt: Date.now() }],
+    )
+
+    const result = tabsReducer(
+      localState,
+      hydrateTabs({
+        tabs: [localTab, deletedTab],
+        activeTabId: 'alive',
+        renameRequestTabId: null,
+        tombstones: [],
+      })
+    )
+
+    const ids = result.tabs.map(t => t.id)
+    expect(ids).toContain('alive')
+    expect(ids).not.toContain('deleted')
+  })
+
+  it('does not resurrect tabs tombstoned in remote', () => {
+    const alive = makeTab({ id: 'alive', title: 'Alive' })
+    const deletedRemotely = makeTab({ id: 'deleted-remote', title: 'Was Deleted' })
+
+    const localState = makeState([alive, deletedRemotely], 'alive')
+
+    const result = tabsReducer(
+      localState,
+      hydrateTabs({
+        tabs: [alive],
+        activeTabId: 'alive',
+        renameRequestTabId: null,
+        tombstones: [{ id: 'deleted-remote', deletedAt: Date.now() }],
+      })
+    )
+
+    const ids = result.tabs.map(t => t.id)
+    expect(ids).toContain('alive')
+    expect(ids).not.toContain('deleted-remote')
+  })
+
+  it('resolves property conflicts using updatedAt — newer wins', () => {
+    const now = Date.now()
+    const localTab = makeTab({ id: 'tab-1', title: 'Local Title', updatedAt: now + 1000 })
+    const remoteTab = makeTab({ id: 'tab-1', title: 'Remote Title', updatedAt: now })
+
+    const localState = makeState([localTab])
+
+    const result = tabsReducer(
+      localState,
+      hydrateTabs({
+        tabs: [remoteTab],
+        activeTabId: 'tab-1',
+        renameRequestTabId: null,
+        tombstones: [],
+      })
+    )
+
+    // Local tab is newer, so local properties win
+    expect(result.tabs[0].title).toBe('Local Title')
+  })
+
+  it('resolves property conflicts — remote wins when newer', () => {
+    const now = Date.now()
+    const localTab = makeTab({ id: 'tab-1', title: 'Local Title', updatedAt: now })
+    const remoteTab = makeTab({ id: 'tab-1', title: 'Remote Title', updatedAt: now + 1000 })
+
+    const localState = makeState([localTab])
+
+    const result = tabsReducer(
+      localState,
+      hydrateTabs({
+        tabs: [remoteTab],
+        activeTabId: 'tab-1',
+        renameRequestTabId: null,
+        tombstones: [],
+      })
+    )
+
+    // Remote tab is newer, so remote properties win
+    expect(result.tabs[0].title).toBe('Remote Title')
+  })
+
+  it('remote wins ties on updatedAt', () => {
+    const now = Date.now()
+    const localTab = makeTab({ id: 'tab-1', title: 'Local', updatedAt: now })
+    const remoteTab = makeTab({ id: 'tab-1', title: 'Remote', updatedAt: now })
+
+    const localState = makeState([localTab])
+
+    const result = tabsReducer(
+      localState,
+      hydrateTabs({
+        tabs: [remoteTab],
+        activeTabId: 'tab-1',
+        renameRequestTabId: null,
+        tombstones: [],
+      })
+    )
+
+    expect(result.tabs[0].title).toBe('Remote')
+  })
+
+  it('uses remote order for shared tabs, appends local-only tabs', () => {
+    const a = makeTab({ id: 'a', title: 'A' })
+    const b = makeTab({ id: 'b', title: 'B' })
+    const c = makeTab({ id: 'c', title: 'C' })
+    const localOnly = makeTab({ id: 'local', title: 'Local' })
+
+    // Local order: a, b, c, local
+    const localState = makeState([a, b, c, localOnly])
+
+    // Remote order is reversed: c, b, a
+    const result = tabsReducer(
+      localState,
+      hydrateTabs({
+        tabs: [c, b, a],
+        activeTabId: 'a',
+        renameRequestTabId: null,
+        tombstones: [],
+      })
+    )
+
+    const ids = result.tabs.map(t => t.id)
+    // Shared tabs use remote order (c, b, a), local-only appended
+    expect(ids).toEqual(['c', 'b', 'a', 'local'])
+  })
+
+  it('preserves local activeTabId if it exists in merged set', () => {
+    const tab1 = makeTab({ id: 't1' })
+    const tab2 = makeTab({ id: 't2' })
+
+    const localState = makeState([tab1], 't1')
+
+    const result = tabsReducer(
+      localState,
+      hydrateTabs({
+        tabs: [tab1, tab2],
+        activeTabId: 't2',
+        renameRequestTabId: null,
+        tombstones: [],
+      })
+    )
+
+    // Local activeTabId is preferred if it exists in merged set
+    expect(result.activeTabId).toBe('t1')
+  })
+
+  it('unions tombstones from both local and remote', () => {
+    const tab = makeTab({ id: 'alive' })
+    const localState = makeState(
+      [tab],
+      'alive',
+      [{ id: 'local-deleted', deletedAt: Date.now() }],
+    )
+
+    const result = tabsReducer(
+      localState,
+      hydrateTabs({
+        tabs: [tab],
+        activeTabId: 'alive',
+        renameRequestTabId: null,
+        tombstones: [{ id: 'remote-deleted', deletedAt: Date.now() }],
+      })
+    )
+
+    const tombstoneIds = result.tombstones.map(t => t.id)
+    expect(tombstoneIds).toContain('local-deleted')
+    expect(tombstoneIds).toContain('remote-deleted')
+  })
+})
+
+describe('removeTab adds tombstone', () => {
+  it('records a tombstone when removing a tab', () => {
+    const tab1 = makeTab({ id: 't1' })
+    const tab2 = makeTab({ id: 't2' })
+    const state = makeState([tab1, tab2], 't1')
+
+    const result = tabsReducer(state, removeTab('t1'))
+
+    expect(result.tabs.map(t => t.id)).toEqual(['t2'])
+    expect(result.tombstones).toHaveLength(1)
+    expect(result.tombstones[0].id).toBe('t1')
+    expect(result.tombstones[0].deletedAt).toBeGreaterThan(0)
+  })
+})
+
+describe('tab mutations set updatedAt', () => {
+  it('addTab sets updatedAt', () => {
+    const before = Date.now()
+    const state = tabsReducer(makeState([]), addTab({ title: 'New' }))
+    const tab = state.tabs[0]
+    expect(tab.updatedAt).toBeGreaterThanOrEqual(before)
+  })
+
+  it('updateTab bumps updatedAt', () => {
+    const tab = makeTab({ id: 't1', updatedAt: 1000 })
+    const state = makeState([tab])
+
+    const before = Date.now()
+    const result = tabsReducer(state, updateTab({ id: 't1', updates: { title: 'Renamed' } }))
+    expect(result.tabs[0].updatedAt).toBeGreaterThanOrEqual(before)
+    expect(result.tabs[0].title).toBe('Renamed')
+  })
+})
diff --git a/test/unit/client/store/tabsSlice.test.ts b/test/unit/client/store/tabsSlice.test.ts
index 56ce6c04..f3a8b80f 100644
--- a/test/unit/client/store/tabsSlice.test.ts
+++ b/test/unit/client/store/tabsSlice.test.ts
@@ -436,7 +436,6 @@ describe('tabsSlice', () => {
         createRequestId: 'full-tab',
         title: 'Full Tab',
         description: 'A description',
-        terminalId: 'terminal-789',
         status: 'running',
         mode: 'codex',
         shell: 'wsl',
@@ -457,7 +456,6 @@ describe('tabsSlice', () => {
       expect(tab.id).toBe('full-tab')
       expect(tab.title).toBe('Full Tab')
       expect(tab.description).toBe('A description')
-      expect(tab.terminalId).toBe('terminal-789')
       expect(tab.status).toBe('running')
       expect(tab.mode).toBe('codex')
       expect(tab.shell).toBe('wsl')
@@ -758,7 +756,11 @@ describe('tabsSlice', () => {
         },
       })
 
-      store.dispatch(addTab({ id: 'tab-1', mode: 'claude', terminalId: 'term-1', status: 'running' }))
+      store.dispatch(addTab({ id: 'tab-1', mode: 'claude', status: 'running' }))
+      store.dispatch(initLayout({
+        tabId: 'tab-1',
+        content: { kind: 'terminal', mode: 'claude', terminalId: 'term-1', status: 'running' },
+      }))
       store.dispatch(addTab({ id: 'tab-2', mode: 'shell' }))
 
       await store.dispatch(openSessionTab({ sessionId: VALID_CLAUDE_SESSION_ID, provider: 'claude', terminalId: 'term-1' }))
@@ -784,9 +786,14 @@ describe('tabsSlice', () => {
 
       const tabs = store.getState().tabs.tabs
       expect(tabs).toHaveLength(1)
-      expect(tabs[0].terminalId).toBe('term-2')
       expect(tabs[0].status).toBe('running')
       expect(tabs[0].resumeSessionId).toBe(VALID_CLAUDE_SESSION_ID)
+      // terminalId lives in pane content, not on the tab
+      const layout = store.getState().panes.layouts[tabs[0].id]
+      expect(layout).toBeDefined()
+      if (layout?.type === 'leaf' && layout.content.kind === 'terminal') {
+        expect(layout.content.terminalId).toBe('term-2')
+      }
     })
 
     it('uses capitalized provider label for codex tab title', async () => {
diff --git a/test/unit/server/session-repair-service.test.ts b/test/unit/server/session-repair-service.test.ts
index 5308adff..2295f0a9 100644
--- a/test/unit/server/session-repair-service.test.ts
+++ b/test/unit/server/session-repair-service.test.ts
@@ -320,4 +320,57 @@ describe('SessionRepairService', () => {
       await service.stop()
     }
   })
+
+  it('returns cached result immediately when session is queued but cache is valid', async () => {
+    const projectDir = path.join(tempDir, '.claude', 'projects', 'test-project')
+    await fs.mkdir(projectDir, { recursive: true })
+
+    const targetSessionId = 'target-session'
+    const targetFile = path.join(projectDir, `${targetSessionId}.jsonl`)
+    await fs.writeFile(targetFile, createTranscript(targetSessionId, '/tmp/target'))
+
+    // Scanner that should never be called for the target session
+    const scan = vi.fn(async (filePath: string): Promise<SessionScanResult> => {
+      await new Promise(() => {}) // block forever
+      throw new Error('unreachable')
+    })
+
+    const service = new SessionRepairService({
+      cacheDir: tempDir,
+      scanner: { scan, repair: vi.fn() } as any,
+    })
+
+    // Seed the cache and session path index
+    const cachedResult: SessionScanResult = {
+      sessionId: targetSessionId,
+      filePath: targetFile,
+      status: 'healthy',
+      chainDepth: 5,
+      orphanCount: 0,
+      fileSize: 100,
+      messageCount: 10,
+    }
+    await (service as any).cache.set(targetFile, cachedResult)
+
+    // Directly enqueue the session in the queue (simulating what discovery does)
+    // but DON'T start the queue, so it stays queued and never processes
+    const queue = (service as any).queue
+    queue.enqueue([{ sessionId: targetSessionId, filePath: targetFile, priority: 'disk' }])
+
+    // Also set the session path index (normally done by discovery)
+    ;(service as any).sessionPathIndex.set(targetSessionId, targetFile)
+
+    // The session is now queued but not processed.
+    // waitForSession should find it via cache and return immediately.
+    const before = Date.now()
+    const result = await service.waitForSession(targetSessionId, 100)
+    const elapsed = Date.now() - before
+
+    expect(result.sessionId).toBe(targetSessionId)
+    expect(result.status).toBe('healthy')
+    expect(result.chainDepth).toBe(5)
+    expect(elapsed).toBeLessThan(50)
+    // Scanner should NOT have been called — cache hit bypassed it
+    expect(scan).not.toHaveBeenCalled()
+  })
 })