diff --git a/src/renderer/src/components/Terminal.tsx b/src/renderer/src/components/Terminal.tsx
index 3c7424de1..34417220c 100644
--- a/src/renderer/src/components/Terminal.tsx
+++ b/src/renderer/src/components/Terminal.tsx
@@ -64,7 +64,7 @@ import {
   anyMountedWorktreeHasLayout as computeAnyMountedWorktreeHasLayout
 } from './terminal/split-group-mount'
 import { focusTerminalTabSurface } from '@/lib/focus-terminal-tab-surface'
-import { setForegroundTerminalWorktreeIds } from '@/lib/foreground-terminal-worktrees'
+import { setForegroundTerminalTabIds } from '@/lib/foreground-terminal-tabs'
 import { appendUniqueOpenFileIds } from './terminal/unsaved-close-queue'
 import { setWindowCloseRequestHandler } from './window-close-request-coordinator'
 import CodexRestartChip from './CodexRestartChip'
@@ -279,23 +279,23 @@ function Terminal(): React.JSX.Element | null {
   const activityTerminalPortals: ActivityTerminalPortalTarget[] = useActivityTerminalPortals(
     activeView === 'activity'
   )
-  const foregroundTerminalWorktreeIds = useMemo(() => {
+  const foregroundTerminalTabIds = useMemo(() => {
     const ids = new Set<string>()
-    if (activeView === 'terminal' && renderedActiveWorktreeId) {
-      ids.add(renderedActiveWorktreeId)
+    if (activeView === 'terminal' && activeTabType === 'terminal' && activeTabId) {
+      ids.add(activeTabId)
     }
     for (const portal of activityTerminalPortals) {
-      ids.add(portal.worktreeId)
+      ids.add(portal.tabId)
     }
     return Array.from(ids)
-  }, [activeView, activityTerminalPortals, renderedActiveWorktreeId])
+  }, [activeTabId, activeTabType, activeView, activityTerminalPortals])
 
   useEffect(() => {
     // Why: hibernation must treat terminals portaled into foreground surfaces
-    // as visible even when they are not the singular active worktree.
-    setForegroundTerminalWorktreeIds(foregroundTerminalWorktreeIds)
-    return () => setForegroundTerminalWorktreeIds([])
-  }, [foregroundTerminalWorktreeIds])
+    // as visible even when they are not the singular active terminal tab.
+    setForegroundTerminalTabIds(foregroundTerminalTabIds)
+    return () => setForegroundTerminalTabIds([])
+  }, [foregroundTerminalTabIds])
 
   const tabs = useMemo(
     () => (renderedActiveWorktreeId ? (tabsByWorktree[renderedActiveWorktreeId] ?? []) : []),
diff --git a/src/renderer/src/components/terminal-pane/TerminalPane.tsx b/src/renderer/src/components/terminal-pane/TerminalPane.tsx
index 4cd9b5eef..27615fced 100644
--- a/src/renderer/src/components/terminal-pane/TerminalPane.tsx
+++ b/src/renderer/src/components/terminal-pane/TerminalPane.tsx
@@ -117,7 +117,7 @@ import { keybindingMatchesAction } from '../../../../shared/keybindings'
 import { pasteTerminalClipboard } from './terminal-clipboard-paste'
 import { scheduleImagePasteWebglAtlasRecovery } from './terminal-webgl-paste-recovery'
 import { restoreTerminalFitToDesktop, restoreTerminalFitsToDesktop } from './terminal-fit-restore'
-import { useVisibleTerminalWorktreeClaim } from './use-visible-terminal-worktree-claim'
+import { useVisibleTerminalTabClaim } from './use-visible-terminal-tab-claim'
 
 // Why: registry lives in a leaf module so the store slice can import it
 // without re-entering the `slice → TerminalPane → store → slice` cycle
@@ -271,7 +271,7 @@ export default function TerminalPane({
   const isVisibleRef = useRef(isVisible)
   isVisibleRef.current = isVisible
 
-  useVisibleTerminalWorktreeClaim({ isVisible, worktreeId })
+  useVisibleTerminalTabClaim({ isVisible, tabId })
 
   const [expandedPaneId, setExpandedPaneId] = useState<number | null>(null)
   // Why: tracked in React state (not derived from managerRef.getPanes().length)
diff --git a/src/renderer/src/components/terminal-pane/use-visible-terminal-worktree-claim.test.ts b/src/renderer/src/components/terminal-pane/use-visible-terminal-tab-claim.test.ts
similarity index 61%
rename from src/renderer/src/components/terminal-pane/use-visible-terminal-worktree-claim.test.ts
rename to src/renderer/src/components/terminal-pane/use-visible-terminal-tab-claim.test.ts
index 79c17b4fc..252c44288 100644
--- a/src/renderer/src/components/terminal-pane/use-visible-terminal-worktree-claim.test.ts
+++ b/src/renderer/src/components/terminal-pane/use-visible-terminal-tab-claim.test.ts
@@ -1,10 +1,10 @@
 import type * as ReactModule from 'react'
 import { afterEach, describe, expect, it, vi } from 'vitest'
 import {
-  getForegroundTerminalWorktreeIds,
-  resetForegroundTerminalWorktreeIdsForTests
-} from '@/lib/foreground-terminal-worktrees'
-import { useVisibleTerminalWorktreeClaim } from './use-visible-terminal-worktree-claim'
+  getForegroundTerminalTabIds,
+  resetForegroundTerminalTabIdsForTests
+} from '@/lib/foreground-terminal-tabs'
+import { useVisibleTerminalTabClaim } from './use-visible-terminal-tab-claim'
 
 const reactEffects = vi.hoisted(() => ({
   layoutEffects: [] as (() => void | (() => void))[],
@@ -25,30 +25,30 @@ vi.mock('react', async (importOriginal) => {
 })
 
 afterEach(() => {
-  resetForegroundTerminalWorktreeIdsForTests()
+  resetForegroundTerminalTabIdsForTests()
   reactEffects.layoutEffects = []
   reactEffects.passiveEffects = []
 })
 
-describe('useVisibleTerminalWorktreeClaim', () => {
+describe('useVisibleTerminalTabClaim', () => {
   it('registers visible panes through a layout effect', () => {
-    useVisibleTerminalWorktreeClaim({ isVisible: true, worktreeId: 'wt-visible' })
+    useVisibleTerminalTabClaim({ isVisible: true, tabId: 'tab-visible' })
 
     expect(reactEffects.passiveEffects).toHaveLength(0)
     expect(reactEffects.layoutEffects).toHaveLength(1)
 
     const cleanup = reactEffects.layoutEffects[0]()
-    expect(getForegroundTerminalWorktreeIds()).toEqual(['wt-visible'])
+    expect(getForegroundTerminalTabIds()).toEqual(['tab-visible'])
 
     cleanup?.()
-    expect(getForegroundTerminalWorktreeIds()).toEqual([])
+    expect(getForegroundTerminalTabIds()).toEqual([])
   })
 
   it('does not claim hidden panes', () => {
-    useVisibleTerminalWorktreeClaim({ isVisible: false, worktreeId: 'wt-hidden' })
+    useVisibleTerminalTabClaim({ isVisible: false, tabId: 'tab-hidden' })
 
     reactEffects.layoutEffects[0]()
 
-    expect(getForegroundTerminalWorktreeIds()).toEqual([])
+    expect(getForegroundTerminalTabIds()).toEqual([])
   })
 })
diff --git a/src/renderer/src/components/terminal-pane/use-visible-terminal-tab-claim.ts b/src/renderer/src/components/terminal-pane/use-visible-terminal-tab-claim.ts
new file mode 100644
index 000000000..9484b7f9d
--- /dev/null
+++ b/src/renderer/src/components/terminal-pane/use-visible-terminal-tab-claim.ts
@@ -0,0 +1,21 @@
+import { useLayoutEffect } from 'react'
+import { registerVisibleTerminalTab } from '@/lib/foreground-terminal-tabs'
+
+type VisibleTerminalTabClaimOptions = {
+  isVisible: boolean
+  tabId: string
+}
+
+export function useVisibleTerminalTabClaim({
+  isVisible,
+  tabId
+}: VisibleTerminalTabClaimOptions): void {
+  useLayoutEffect(() => {
+    if (!isVisible) {
+      return
+    }
+    // Why: agent sleep must fail closed before paint for any pane the user can
+    // see, even when global active-worktree state is between views.
+    return registerVisibleTerminalTab(tabId)
+  }, [isVisible, tabId])
+}
diff --git a/src/renderer/src/components/terminal-pane/use-visible-terminal-worktree-claim.ts b/src/renderer/src/components/terminal-pane/use-visible-terminal-worktree-claim.ts
deleted file mode 100644
index 9cb69bf84..000000000
--- a/src/renderer/src/components/terminal-pane/use-visible-terminal-worktree-claim.ts
+++ /dev/null
@@ -1,21 +0,0 @@
-import { useLayoutEffect } from 'react'
-import { registerVisibleTerminalWorktree } from '@/lib/foreground-terminal-worktrees'
-
-type VisibleTerminalWorktreeClaimOptions = {
-  isVisible: boolean
-  worktreeId: string
-}
-
-export function useVisibleTerminalWorktreeClaim({
-  isVisible,
-  worktreeId
-}: VisibleTerminalWorktreeClaimOptions): void {
-  useLayoutEffect(() => {
-    if (!isVisible) {
-      return
-    }
-    // Why: agent sleep must fail closed before paint for any pane the user can
-    // see, even when global active-worktree state is between views.
-    return registerVisibleTerminalWorktree(worktreeId)
-  }, [isVisible, worktreeId])
-}
diff --git a/src/renderer/src/lib/agent-hibernation-confirmation.test.ts b/src/renderer/src/lib/agent-hibernation-confirmation.test.ts
new file mode 100644
index 000000000..f24c8dec7
--- /dev/null
+++ b/src/renderer/src/lib/agent-hibernation-confirmation.test.ts
@@ -0,0 +1,34 @@
+import { describe, expect, it } from 'vitest'
+import type { AgentHibernationCandidate } from './agent-hibernation-planner'
+import { confirmAgentHibernationCandidates } from './agent-hibernation-confirmation'
+
+function candidate(overrides: Partial<AgentHibernationCandidate> = {}): AgentHibernationCandidate {
+  return {
+    id: 'wt-bg|tab-1:leaf-1',
+    worktreeId: 'wt-bg',
+    paneKey: 'tab-1:leaf-1',
+    tabId: 'tab-1',
+    leafId: 'leaf-1',
+    paneKeys: ['tab-1:leaf-1'],
+    targetPtyIds: ['pty-1'],
+    expectedRuntimePtyIds: ['pty-1'],
+    signature: 'stable-signature',
+    ...overrides
+  }
+}
+
+describe('agent sleep confirmation', () => {
+  it('requires two stable ticks and resets on signature changes', () => {
+    const firstCandidate = candidate()
+    const first = confirmAgentHibernationCandidates({}, [firstCandidate])
+    expect(first.candidates).toEqual([])
+    expect(
+      confirmAgentHibernationCandidates(first.confirmationState, [firstCandidate]).candidates
+    ).toEqual([firstCandidate])
+
+    const changed = candidate({ signature: 'changed-signature' })
+    expect(
+      confirmAgentHibernationCandidates(first.confirmationState, [changed]).candidates
+    ).toEqual([])
+  })
+})
diff --git a/src/renderer/src/lib/agent-hibernation-confirmation.ts b/src/renderer/src/lib/agent-hibernation-confirmation.ts
new file mode 100644
index 000000000..cd00381e8
--- /dev/null
+++ b/src/renderer/src/lib/agent-hibernation-confirmation.ts
@@ -0,0 +1,23 @@
+import type { AgentHibernationCandidate } from './agent-hibernation-planner'
+
+export type AgentHibernationConfirmationState = Record<string, string>
+
+export type AgentHibernationPlan = {
+  candidates: AgentHibernationCandidate[]
+  confirmationState: AgentHibernationConfirmationState
+}
+
+export function confirmAgentHibernationCandidates(
+  previous: AgentHibernationConfirmationState,
+  candidates: AgentHibernationCandidate[]
+): AgentHibernationPlan {
+  const confirmationState: AgentHibernationConfirmationState = {}
+  const confirmed: AgentHibernationCandidate[] = []
+  for (const candidate of candidates) {
+    confirmationState[candidate.id] = candidate.signature
+    if (previous[candidate.id] === candidate.signature) {
+      confirmed.push(candidate)
+    }
+  }
+  return { candidates: confirmed, confirmationState }
+}
diff --git a/src/renderer/src/lib/agent-hibernation-coordinator.test.ts b/src/renderer/src/lib/agent-hibernation-coordinator.test.ts
index 297eb1b08..2a3bc5d7d 100644
--- a/src/renderer/src/lib/agent-hibernation-coordinator.test.ts
+++ b/src/renderer/src/lib/agent-hibernation-coordinator.test.ts
@@ -5,14 +5,15 @@ import { useAppStore } from '@/store'
 import { DEFAULT_AGENT_HIBERNATION_IDLE_MS } from './agent-hibernation-planner'
 import {
   resetAgentHibernationCoordinatorForTests,
+  runAgentHibernationTick,
   startAgentHibernationCoordinator
 } from './agent-hibernation-coordinator'
 import { hydrateDrivers, setDriverForPty } from './pane-manager/mobile-driver-state'
 import {
-  registerVisibleTerminalWorktree,
-  resetForegroundTerminalWorktreeIdsForTests,
-  setForegroundTerminalWorktreeIds
-} from './foreground-terminal-worktrees'
+  registerVisibleTerminalTab,
+  resetForegroundTerminalTabIdsForTests,
+  setForegroundTerminalTabIds
+} from './foreground-terminal-tabs'
 import {
   recordAgentHibernationPaneOutput,
   resetAgentHibernationOutputActivityForTests
@@ -163,7 +164,7 @@ function deferred<T>(): {
 afterEach(() => {
   resetAgentHibernationCoordinatorForTests()
   clearRuntimeCompatibilityCacheForTests()
-  resetForegroundTerminalWorktreeIdsForTests()
+  resetForegroundTerminalTabIdsForTests()
   resetAgentHibernationOutputActivityForTests()
   hydrateDrivers([])
   mockRuntimeEnvironmentCall.mockReset()
@@ -229,10 +230,10 @@ describe('agent sleep coordinator', () => {
     expect(shutdown).not.toHaveBeenCalled()
   })
 
-  it('does not hibernate a foreground worktree that is not the active worktree', async () => {
+  it('does not hibernate a foreground terminal tab that is not in the active worktree', async () => {
     vi.useFakeTimers()
     const shutdown = installEligibleState(vi.fn().mockResolvedValue(undefined))
-    setForegroundTerminalWorktreeIds(['wt-bg'])
+    setForegroundTerminalTabIds(['tab-1'])
     startAgentHibernationCoordinator({ intervalMs: 1000, now: () => NOW })
 
     await vi.advanceTimersByTimeAsync(3000)
@@ -240,21 +241,27 @@ describe('agent sleep coordinator', () => {
     expect(shutdown).not.toHaveBeenCalled()
   })
 
-  it('does not hibernate a worktree with a visible mounted terminal pane', async () => {
+  it('does not hibernate a visible mounted terminal tab', async () => {
     vi.useFakeTimers()
+    vi.setSystemTime(NOW)
     const shutdown = installEligibleState(vi.fn().mockResolvedValue(undefined))
-    const unregister = registerVisibleTerminalWorktree('wt-bg')
-    startAgentHibernationCoordinator({ intervalMs: 1000, now: () => NOW })
+    const unregister = registerVisibleTerminalTab('tab-1')
 
-    await vi.advanceTimersByTimeAsync(3000)
+    await runAgentHibernationTick()
     expect(shutdown).not.toHaveBeenCalled()
 
+    vi.setSystemTime(NOW + 1_000)
     unregister()
-    // Why: the coordinator requires one tick to confirm a stable candidate
-    // and a second tick to revalidate before shutdown.
-    await vi.advanceTimersByTimeAsync(1000)
-    await vi.advanceTimersByTimeAsync(1000)
+    await runAgentHibernationTick()
+    expect(shutdown).not.toHaveBeenCalled()
 
+    vi.setSystemTime(NOW + 1_000 + DEFAULT_AGENT_HIBERNATION_IDLE_MS + 1)
+    await runAgentHibernationTick()
+    expect(shutdown).not.toHaveBeenCalled()
+
+    await runAgentHibernationTick()
+    await Promise.resolve()
+    await Promise.resolve()
     expect(shutdown).toHaveBeenCalledWith('wt-bg', {
       paneKey: `tab-1:${LEAF}`,
       tabId: 'tab-1',
@@ -292,6 +299,37 @@ describe('agent sleep coordinator', () => {
     expect(shutdown).not.toHaveBeenCalled()
   })
 
+  it('restarts confirmation when a foreground terminal visit refreshes idle state', async () => {
+    vi.useFakeTimers()
+    vi.setSystemTime(NOW)
+    const shutdown = installEligibleState(vi.fn().mockResolvedValue(undefined))
+
+    await runAgentHibernationTick()
+    expect(shutdown).not.toHaveBeenCalled()
+
+    vi.setSystemTime(NOW + 1_999)
+    setForegroundTerminalTabIds(['tab-1'])
+    vi.setSystemTime(NOW + 2_000)
+    setForegroundTerminalTabIds([])
+
+    await runAgentHibernationTick()
+    expect(shutdown).not.toHaveBeenCalled()
+
+    vi.setSystemTime(NOW + 2_000 + DEFAULT_AGENT_HIBERNATION_IDLE_MS + 1)
+    await runAgentHibernationTick()
+    expect(shutdown).not.toHaveBeenCalled()
+
+    await runAgentHibernationTick()
+    await Promise.resolve()
+    await Promise.resolve()
+    expect(shutdown).toHaveBeenCalledWith('wt-bg', {
+      paneKey: `tab-1:${LEAF}`,
+      tabId: 'tab-1',
+      leafId: LEAF,
+      ptyId: 'pty-1'
+    })
+  })
+
   it('blocks shutdown when terminal input arrives between confirmation ticks', async () => {
     vi.useFakeTimers()
     const shutdown = installEligibleState(vi.fn().mockResolvedValue(undefined))
diff --git a/src/renderer/src/lib/agent-hibernation-coordinator.ts b/src/renderer/src/lib/agent-hibernation-coordinator.ts
index b6d4c12a5..d410a1278 100644
--- a/src/renderer/src/lib/agent-hibernation-coordinator.ts
+++ b/src/renderer/src/lib/agent-hibernation-coordinator.ts
@@ -1,14 +1,19 @@
 import { useAppStore } from '@/store'
 import {
-  confirmAgentHibernationCandidates,
   planAgentHibernationCandidates,
   type AgentHibernationCandidate,
-  type AgentHibernationConfirmationState,
   type AgentHibernationPlannerSnapshot
 } from './agent-hibernation-planner'
+import {
+  confirmAgentHibernationCandidates,
+  type AgentHibernationConfirmationState
+} from './agent-hibernation-confirmation'
 import type { AppState } from '@/store/types'
 import { getAllDrivers } from './pane-manager/mobile-driver-state'
-import { getForegroundTerminalWorktreeIds } from './foreground-terminal-worktrees'
+import {
+  getForegroundTerminalTabIds,
+  getForegroundTerminalTabLastSeenAtById
+} from './foreground-terminal-tabs'
 import { getAgentHibernationOutputSignature } from './agent-hibernation-output-activity'
 import { getRuntimeEnvironmentIdForWorktree } from './worktree-runtime-owner'
 import { callRuntimeRpc } from '@/runtime/runtime-rpc-client'
@@ -56,7 +61,7 @@ function snapshotFromState(
   return {
     settings: state.settings,
     activeWorktreeId: state.activeWorktreeId,
-    foregroundWorktreeIds: getForegroundTerminalWorktreeIds(),
+    foregroundTerminalTabIds: getForegroundTerminalTabIds(),
     tabsByWorktree: state.tabsByWorktree,
     terminalLayoutsByTabId: state.terminalLayoutsByTabId,
     ptyIdsByTabId: state.ptyIdsByTabId,
@@ -68,6 +73,7 @@ function snapshotFromState(
     agentStatusByPaneKey: state.agentStatusByPaneKey,
     sleepingAgentSessionsByPaneKey: state.sleepingAgentSessionsByPaneKey,
     lastTerminalInputAtByPaneKey: state.lastTerminalInputAtByPaneKey,
+    foregroundTerminalLastSeenAtByTabId: getForegroundTerminalTabLastSeenAtById(),
     now
   }
 }
diff --git a/src/renderer/src/lib/agent-hibernation-planner.test.ts b/src/renderer/src/lib/agent-hibernation-planner.test.ts
index 1c6290534..79064f312 100644
--- a/src/renderer/src/lib/agent-hibernation-planner.test.ts
+++ b/src/renderer/src/lib/agent-hibernation-planner.test.ts
@@ -5,7 +5,6 @@ import {
   DEFAULT_AGENT_HIBERNATION_IDLE_MS,
   MAX_AGENT_HIBERNATION_IDLE_MS,
   MIN_AGENT_HIBERNATION_IDLE_MS,
-  confirmAgentHibernationCandidates,
   getEffectiveAgentHibernationIdleMs,
   planAgentHibernationCandidates,
   type AgentHibernationPlannerSnapshot
@@ -65,7 +64,7 @@ function snapshot(
       agentHibernationIdleMs: DEFAULT_AGENT_HIBERNATION_IDLE_MS
     },
     activeWorktreeId: 'wt-active',
-    foregroundWorktreeIds: ['wt-active'],
+    foregroundTerminalTabIds: [],
     tabsByWorktree: { 'wt-bg': [tab()] },
     terminalLayoutsByTabId: { 'tab-1': layout() },
     ptyIdsByTabId: { 'tab-1': ['pty-1'] },
@@ -73,6 +72,7 @@ function snapshot(
     agentStatusByPaneKey: { [agentEntry.paneKey]: agentEntry },
     sleepingAgentSessionsByPaneKey: {},
     lastTerminalInputAtByPaneKey: {},
+    foregroundTerminalLastSeenAtByTabId: {},
     now: NOW,
     ...overrides
   }
@@ -99,9 +99,7 @@ describe('agent sleep planner', () => {
       )
     ).toEqual([])
     expect(plannedWorktrees(snapshot({ activeWorktreeId: 'wt-bg' }))).toEqual([])
-    expect(plannedWorktrees(snapshot({ foregroundWorktreeIds: ['wt-active', 'wt-bg'] }))).toEqual(
-      []
-    )
+    expect(plannedWorktrees(snapshot({ foregroundTerminalTabIds: ['tab-1'] }))).toEqual([])
   })
 
   it('requires done resumable provider-session entries', () => {
@@ -136,6 +134,89 @@ describe('agent sleep planner', () => {
     ).toEqual(['wt-bg'])
   })
 
+  it('uses foreground terminal tab last-seen as the idle baseline when it is newer', () => {
+    expect(
+      plannedWorktrees(
+        snapshot({
+          foregroundTerminalLastSeenAtByTabId: {
+            'tab-1': NOW - DEFAULT_AGENT_HIBERNATION_IDLE_MS + 1
+          }
+        })
+      )
+    ).toEqual([])
+    expect(
+      plannedWorktrees(
+        snapshot({
+          foregroundTerminalLastSeenAtByTabId: {
+            'tab-1': NOW - DEFAULT_AGENT_HIBERNATION_IDLE_MS - 1
+          }
+        })
+      )
+    ).toEqual(['wt-bg'])
+    expect(
+      plannedWorktrees(
+        snapshot({
+          foregroundTerminalLastSeenAtByTabId: {
+            'tab-1': NOW - DEFAULT_AGENT_HIBERNATION_IDLE_MS - 1
+          },
+          lastTerminalInputAtByPaneKey: { [`tab-1:${LEAF}`]: OLD + 1 }
+        })
+      )
+    ).toEqual([])
+  })
+
+  it('does not let one foreground terminal tab reset a sibling tab in the same worktree', () => {
+    const siblingEntry = entry({
+      paneKey: `tab-2:${OTHER_LEAF}`,
+      tabId: 'tab-2',
+      providerSession: { key: 'session_id', id: 'session-2' }
+    })
+
+    expect(
+      plannedPaneKeys(
+        snapshot({
+          foregroundTerminalTabIds: ['tab-1'],
+          foregroundTerminalLastSeenAtByTabId: {
+            'tab-1': NOW
+          },
+          tabsByWorktree: { 'wt-bg': [tab('tab-1'), tab('tab-2')] },
+          terminalLayoutsByTabId: {
+            'tab-1': layout(),
+            'tab-2': layout(OTHER_LEAF, 'pty-2')
+          },
+          ptyIdsByTabId: {
+            'tab-1': ['pty-1'],
+            'tab-2': ['pty-2']
+          },
+          agentStatusByPaneKey: {
+            [`tab-1:${LEAF}`]: entry(),
+            [siblingEntry.paneKey]: siblingEntry
+          }
+        })
+      )
+    ).toEqual([`tab-2:${OTHER_LEAF}`])
+  })
+
+  it('includes the effective idle start in the candidate signature', () => {
+    const oldEntry = entry({
+      updatedAt: NOW - DEFAULT_AGENT_HIBERNATION_IDLE_MS - 10_000,
+      stateStartedAt: NOW - DEFAULT_AGENT_HIBERNATION_IDLE_MS - 10_000
+    })
+    const [withoutVisit] = planAgentHibernationCandidates(
+      snapshot({ agentStatusByPaneKey: { [oldEntry.paneKey]: oldEntry } })
+    )
+    const [withVisit] = planAgentHibernationCandidates(
+      snapshot({
+        agentStatusByPaneKey: { [oldEntry.paneKey]: oldEntry },
+        foregroundTerminalLastSeenAtByTabId: {
+          'tab-1': NOW - DEFAULT_AGENT_HIBERNATION_IDLE_MS - 1
+        }
+      })
+    )
+
+    expect(withoutVisit.signature).not.toEqual(withVisit.signature)
+  })
+
   it('emits a pane candidate when a sibling shell PTY is live', () => {
     expect(
       planAgentHibernationCandidates(
@@ -309,19 +390,6 @@ describe('agent sleep planner', () => {
     ).toEqual([`tab-1:${LEAF}`, `tab-1:${OTHER_LEAF}`])
   })
 
-  it('requires two stable ticks and resets on signature changes', () => {
-    const [candidate] = planAgentHibernationCandidates(snapshot())
-    const first = confirmAgentHibernationCandidates({}, [candidate])
-    expect(first.candidates).toEqual([])
-    expect(
-      confirmAgentHibernationCandidates(first.confirmationState, [candidate]).candidates
-    ).toEqual([candidate])
-    const changed = { ...candidate, signature: `${candidate.signature}:changed` }
-    expect(
-      confirmAgentHibernationCandidates(first.confirmationState, [changed]).candidates
-    ).toEqual([])
-  })
-
   it('clamps corrupt or out-of-range idle durations to the default', () => {
     expect(getEffectiveAgentHibernationIdleMs(0)).toBe(DEFAULT_AGENT_HIBERNATION_IDLE_MS)
     expect(getEffectiveAgentHibernationIdleMs(Number.NaN)).toBe(DEFAULT_AGENT_HIBERNATION_IDLE_MS)
diff --git a/src/renderer/src/lib/agent-hibernation-planner.ts b/src/renderer/src/lib/agent-hibernation-planner.ts
index 43f41bd57..a83943dd2 100644
--- a/src/renderer/src/lib/agent-hibernation-planner.ts
+++ b/src/renderer/src/lib/agent-hibernation-planner.ts
@@ -15,7 +15,7 @@ export const MAX_AGENT_HIBERNATION_IDLE_MS = 24 * 60 * 60 * 1000
 export type AgentHibernationPlannerSnapshot = {
   settings: Pick<GlobalSettings, 'experimentalAgentHibernation' | 'agentHibernationIdleMs'> | null
   activeWorktreeId: string | null
-  foregroundWorktreeIds: string[]
+  foregroundTerminalTabIds: string[]
   tabsByWorktree: Record<string, TerminalTab[]>
   terminalLayoutsByTabId: Record<string, TerminalLayoutSnapshot | undefined>
   ptyIdsByTabId: Record<string, string[] | undefined>
@@ -25,6 +25,7 @@ export type AgentHibernationPlannerSnapshot = {
   agentStatusByPaneKey: Record<string, AgentStatusEntry | undefined>
   sleepingAgentSessionsByPaneKey: Record<string, SleepingAgentSessionRecord | undefined>
   lastTerminalInputAtByPaneKey: Record<string, number | undefined>
+  foregroundTerminalLastSeenAtByTabId: Record<string, number | undefined>
   now: number
 }
 
@@ -40,13 +41,6 @@ export type AgentHibernationCandidate = {
   signature: string
 }
 
-export type AgentHibernationConfirmationState = Record<string, string>
-
-export type AgentHibernationPlan = {
-  candidates: AgentHibernationCandidate[]
-  confirmationState: AgentHibernationConfirmationState
-}
-
 type EligiblePane = {
   paneKey: string
   tabId: string
@@ -56,6 +50,7 @@ type EligiblePane = {
   providerSessionId: string
   state: AgentStatusEntry['state']
   updatedAt: number
+  effectiveIdleStart: number
   inputAt: number
 }
 
@@ -120,6 +115,7 @@ function getEligiblePane(args: {
   livePtyIds: Set<string>
   sleepingAgentSessionsByPaneKey: AgentHibernationPlannerSnapshot['sleepingAgentSessionsByPaneKey']
   lastTerminalInputAtByPaneKey: AgentHibernationPlannerSnapshot['lastTerminalInputAtByPaneKey']
+  foregroundTerminalLastSeenAtByTabId: AgentHibernationPlannerSnapshot['foregroundTerminalLastSeenAtByTabId']
   mobileLockedPtyIds: Set<string>
   now: number
   idleMs: number
@@ -131,6 +127,7 @@ function getEligiblePane(args: {
     livePtyIds,
     sleepingAgentSessionsByPaneKey,
     lastTerminalInputAtByPaneKey,
+    foregroundTerminalLastSeenAtByTabId,
     mobileLockedPtyIds
   } = args
   if (
@@ -152,7 +149,16 @@ function getEligiblePane(args: {
   if (!getAgentResumeArgv(entry.agentType, entry.providerSession)) {
     return null
   }
-  if (args.now - entry.updatedAt < args.idleMs) {
+  // Why: returning to the containing terminal tab should restart sleep even
+  // without pane input; sibling tabs in the worktree should keep their age.
+  const foregroundLastSeenAt = foregroundTerminalLastSeenAtByTabId[tab.id]
+  const effectiveIdleStart = Math.max(
+    entry.updatedAt,
+    typeof foregroundLastSeenAt === 'number' && Number.isFinite(foregroundLastSeenAt)
+      ? foregroundLastSeenAt
+      : 0
+  )
+  if (args.now - effectiveIdleStart < args.idleMs) {
     return null
   }
   const inputAt = lastTerminalInputAtByPaneKey[entry.paneKey]
@@ -177,6 +183,7 @@ function getEligiblePane(args: {
     providerSessionId: entry.providerSession.id,
     state: entry.state,
     updatedAt: entry.updatedAt,
+    effectiveIdleStart,
     inputAt: typeof inputAt === 'number' && Number.isFinite(inputAt) ? inputAt : 0
   }
 }
@@ -187,7 +194,7 @@ function signatureFor(worktreeId: string, panes: EligiblePane[]): string {
     .sort((a, b) => a.paneKey.localeCompare(b.paneKey))
     .map(
       (pane) =>
-        `${pane.paneKey}:${pane.ptyId}:${pane.runtimePtyId}:${pane.providerSessionId}:${pane.state}:${pane.updatedAt}:${pane.inputAt}`
+        `${pane.paneKey}:${pane.ptyId}:${pane.runtimePtyId}:${pane.providerSessionId}:${pane.state}:${pane.updatedAt}:${pane.effectiveIdleStart}:${pane.inputAt}`
     )
   return `${worktreeId}|${parts.join('|')}`
 }
@@ -226,19 +233,14 @@ export function planAgentHibernationCandidates(
   }
   const idleMs = getEffectiveAgentHibernationIdleMs(snapshot.settings.agentHibernationIdleMs)
   const mobileLockedPtyIds = new Set(snapshot.mobileLockedPtyIds.map(toRuntimePtyId))
-  const foregroundWorktreeIds = new Set(snapshot.foregroundWorktreeIds)
+  const foregroundTerminalTabIds = new Set(snapshot.foregroundTerminalTabIds)
   const runtimeLivenessRequiredWorktreeIds = new Set(
     snapshot.runtimeLivenessRequiredWorktreeIds ?? []
   )
   const agentEntriesByTabId = getAgentEntriesByTabId(snapshot.agentStatusByPaneKey)
   const candidates: AgentHibernationCandidate[] = []
   for (const [worktreeId, tabs] of Object.entries(snapshot.tabsByWorktree)) {
-    if (
-      !worktreeId ||
-      worktreeId === snapshot.activeWorktreeId ||
-      foregroundWorktreeIds.has(worktreeId) ||
-      tabs.length === 0
-    ) {
+    if (!worktreeId || worktreeId === snapshot.activeWorktreeId || tabs.length === 0) {
       continue
     }
     if (
@@ -251,6 +253,9 @@ export function planAgentHibernationCandidates(
       continue
     }
     for (const tab of tabs) {
+      if (foregroundTerminalTabIds.has(tab.id)) {
+        continue
+      }
       const tabLivePtyIds = getLivePtyIdsForTab(
         tab,
         snapshot.ptyIdsByTabId,
@@ -269,6 +274,7 @@ export function planAgentHibernationCandidates(
           livePtyIds: new Set(tabLivePtyIds),
           sleepingAgentSessionsByPaneKey: snapshot.sleepingAgentSessionsByPaneKey,
           lastTerminalInputAtByPaneKey: snapshot.lastTerminalInputAtByPaneKey,
+          foregroundTerminalLastSeenAtByTabId: snapshot.foregroundTerminalLastSeenAtByTabId,
           mobileLockedPtyIds,
           now: snapshot.now,
           idleMs
@@ -293,18 +299,3 @@ export function planAgentHibernationCandidates(
     (a, b) => a.worktreeId.localeCompare(b.worktreeId) || a.paneKey.localeCompare(b.paneKey)
   )
 }
-
-export function confirmAgentHibernationCandidates(
-  previous: AgentHibernationConfirmationState,
-  candidates: AgentHibernationCandidate[]
-): AgentHibernationPlan {
-  const confirmationState: AgentHibernationConfirmationState = {}
-  const confirmed: AgentHibernationCandidate[] = []
-  for (const candidate of candidates) {
-    confirmationState[candidate.id] = candidate.signature
-    if (previous[candidate.id] === candidate.signature) {
-      confirmed.push(candidate)
-    }
-  }
-  return { candidates: confirmed, confirmationState }
-}
diff --git a/src/renderer/src/lib/foreground-terminal-tabs.test.ts b/src/renderer/src/lib/foreground-terminal-tabs.test.ts
new file mode 100644
index 000000000..5b829fdf1
--- /dev/null
+++ b/src/renderer/src/lib/foreground-terminal-tabs.test.ts
@@ -0,0 +1,119 @@
+import { afterEach, describe, expect, it, vi } from 'vitest'
+import {
+  getForegroundTerminalTabIds,
+  getForegroundTerminalTabLastSeenAtById,
+  registerVisibleTerminalTab,
+  resetForegroundTerminalTabIdsForTests,
+  setForegroundTerminalTabIds
+} from './foreground-terminal-tabs'
+
+afterEach(() => {
+  resetForegroundTerminalTabIdsForTests()
+  vi.useRealTimers()
+})
+
+describe('foreground terminal tabs', () => {
+  it('returns the union of explicit foreground ids and visible terminal claims', () => {
+    setForegroundTerminalTabIds(['tab-explicit', null, '', undefined])
+    const unregister = registerVisibleTerminalTab('tab-visible')
+
+    expect(getForegroundTerminalTabIds().sort()).toEqual(['tab-explicit', 'tab-visible'])
+
+    unregister()
+    expect(getForegroundTerminalTabIds()).toEqual(['tab-explicit'])
+  })
+
+  it('keeps duplicate visible terminal tab claims until every token unregisters', () => {
+    const unregisterFirst = registerVisibleTerminalTab('tab-visible')
+    const unregisterSecond = registerVisibleTerminalTab('tab-visible')
+
+    expect(getForegroundTerminalTabIds()).toEqual(['tab-visible'])
+
+    unregisterFirst()
+    expect(getForegroundTerminalTabIds()).toEqual(['tab-visible'])
+
+    unregisterSecond()
+    expect(getForegroundTerminalTabIds()).toEqual([])
+  })
+
+  it('records last-seen timestamps for explicit foreground entries and clears them in tests', () => {
+    vi.useFakeTimers()
+    vi.setSystemTime(1_000)
+
+    setForegroundTerminalTabIds(['tab-explicit', null, '', undefined])
+
+    expect(getForegroundTerminalTabLastSeenAtById()).toEqual({ 'tab-explicit': 1_000 })
+
+    resetForegroundTerminalTabIdsForTests()
+    expect(getForegroundTerminalTabLastSeenAtById()).toEqual({})
+  })
+
+  it('refreshes last-seen when explicit foreground ids leave the combined foreground set', () => {
+    vi.useFakeTimers()
+    vi.setSystemTime(1_000)
+    setForegroundTerminalTabIds(['tab-old'])
+
+    vi.setSystemTime(2_000)
+    setForegroundTerminalTabIds(['tab-new'])
+
+    expect(getForegroundTerminalTabLastSeenAtById()).toEqual({
+      'tab-old': 2_000,
+      'tab-new': 2_000
+    })
+  })
+
+  it('does not refresh an explicit foreground removal while a visible claim remains', () => {
+    vi.useFakeTimers()
+    vi.setSystemTime(1_000)
+    setForegroundTerminalTabIds(['tab-combined'])
+
+    vi.setSystemTime(2_000)
+    const unregister = registerVisibleTerminalTab('tab-combined')
+
+    vi.setSystemTime(3_000)
+    setForegroundTerminalTabIds([])
+
+    expect(getForegroundTerminalTabIds()).toEqual(['tab-combined'])
+    expect(getForegroundTerminalTabLastSeenAtById()).toEqual({ 'tab-combined': 2_000 })
+
+    vi.setSystemTime(4_000)
+    unregister()
+
+    expect(getForegroundTerminalTabLastSeenAtById()).toEqual({ 'tab-combined': 4_000 })
+  })
+
+  it('refreshes visible-claim last-seen only when the last claim leaves', () => {
+    vi.useFakeTimers()
+    vi.setSystemTime(1_000)
+    const unregisterFirst = registerVisibleTerminalTab('tab-visible')
+
+    vi.setSystemTime(2_000)
+    const unregisterSecond = registerVisibleTerminalTab('tab-visible')
+
+    vi.setSystemTime(3_000)
+    unregisterFirst()
+
+    expect(getForegroundTerminalTabIds()).toEqual(['tab-visible'])
+    expect(getForegroundTerminalTabLastSeenAtById()).toEqual({ 'tab-visible': 2_000 })
+
+    vi.setSystemTime(4_000)
+    unregisterSecond()
+
+    expect(getForegroundTerminalTabIds()).toEqual([])
+    expect(getForegroundTerminalTabLastSeenAtById()).toEqual({ 'tab-visible': 4_000 })
+  })
+
+  it('keeps visible-claim cleanup idempotent for last-seen timestamps', () => {
+    vi.useFakeTimers()
+    vi.setSystemTime(1_000)
+    const unregister = registerVisibleTerminalTab('tab-visible')
+
+    vi.setSystemTime(2_000)
+    unregister()
+
+    vi.setSystemTime(3_000)
+    unregister()
+
+    expect(getForegroundTerminalTabLastSeenAtById()).toEqual({ 'tab-visible': 2_000 })
+  })
+})
diff --git a/src/renderer/src/lib/foreground-terminal-tabs.ts b/src/renderer/src/lib/foreground-terminal-tabs.ts
new file mode 100644
index 000000000..7824598db
--- /dev/null
+++ b/src/renderer/src/lib/foreground-terminal-tabs.ts
@@ -0,0 +1,75 @@
+let explicitForegroundTerminalTabIds = new Set<string>()
+const visibleTerminalTabClaimsByToken = new Map<symbol, string>()
+const foregroundTerminalTabLastSeenAtById = new Map<string, number>()
+
+function normalizeTerminalTabIds(tabIds: Iterable<string | null | undefined>): Set<string> {
+  return new Set(
+    Array.from(tabIds).filter(
+      (tabId): tabId is string => typeof tabId === 'string' && tabId.length > 0
+    )
+  )
+}
+
+export function setForegroundTerminalTabIds(tabIds: Iterable<string | null | undefined>): void {
+  const previousForegroundTerminalTabIds = new Set(getForegroundTerminalTabIds())
+  explicitForegroundTerminalTabIds = normalizeTerminalTabIds(tabIds)
+  const now = Date.now()
+  for (const tabId of explicitForegroundTerminalTabIds) {
+    foregroundTerminalTabLastSeenAtById.set(tabId, now)
+  }
+  refreshExitedForegroundTerminalTabLastSeen(previousForegroundTerminalTabIds, now)
+}
+
+export function registerVisibleTerminalTab(tabId: string | null | undefined): () => void {
+  const normalized = normalizeTerminalTabIds([tabId])
+  const id = Array.from(normalized)[0]
+  if (!id) {
+    return () => {}
+  }
+
+  // Why: multiple visible panes can belong to one terminal tab; tokenized claims
+  // let each pane clean up without dropping sibling foreground protection.
+  const token = Symbol(id)
+  visibleTerminalTabClaimsByToken.set(token, id)
+  foregroundTerminalTabLastSeenAtById.set(id, Date.now())
+  return () => {
+    if (!visibleTerminalTabClaimsByToken.delete(token)) {
+      return
+    }
+    if (!getForegroundTerminalTabIds().includes(id)) {
+      // Why: keep the sleep timer anchored to the end of the full foreground visit.
+      foregroundTerminalTabLastSeenAtById.set(id, Date.now())
+    }
+  }
+}
+
+export function getForegroundTerminalTabIds(): string[] {
+  // Why: hibernation already reasons by terminal tab, so visible pane claims
+  // join the page-level foreground set instead of adding pane rules.
+  return Array.from(
+    new Set([...explicitForegroundTerminalTabIds, ...visibleTerminalTabClaimsByToken.values()])
+  )
+}
+
+export function getForegroundTerminalTabLastSeenAtById(): Record<string, number> {
+  return Object.fromEntries(foregroundTerminalTabLastSeenAtById)
+}
+
+export function resetForegroundTerminalTabIdsForTests(): void {
+  explicitForegroundTerminalTabIds = new Set()
+  visibleTerminalTabClaimsByToken.clear()
+  foregroundTerminalTabLastSeenAtById.clear()
+}
+
+function refreshExitedForegroundTerminalTabLastSeen(
+  previousForegroundTerminalTabIds: Set<string>,
+  now: number
+): void {
+  const currentForegroundTerminalTabIds = new Set(getForegroundTerminalTabIds())
+  for (const tabId of previousForegroundTerminalTabIds) {
+    if (!currentForegroundTerminalTabIds.has(tabId)) {
+      // Why: visible panes can keep a terminal tab foreground after explicit ids change.
+      foregroundTerminalTabLastSeenAtById.set(tabId, now)
+    }
+  }
+}
diff --git a/src/renderer/src/lib/foreground-terminal-worktrees.test.ts b/src/renderer/src/lib/foreground-terminal-worktrees.test.ts
deleted file mode 100644
index dcffad497..000000000
--- a/src/renderer/src/lib/foreground-terminal-worktrees.test.ts
+++ /dev/null
@@ -1,36 +0,0 @@
-import { afterEach, describe, expect, it } from 'vitest'
-import {
-  getForegroundTerminalWorktreeIds,
-  registerVisibleTerminalWorktree,
-  resetForegroundTerminalWorktreeIdsForTests,
-  setForegroundTerminalWorktreeIds
-} from './foreground-terminal-worktrees'
-
-afterEach(() => {
-  resetForegroundTerminalWorktreeIdsForTests()
-})
-
-describe('foreground terminal worktrees', () => {
-  it('returns the union of explicit foreground ids and visible terminal claims', () => {
-    setForegroundTerminalWorktreeIds(['wt-explicit', null, '', undefined])
-    const unregister = registerVisibleTerminalWorktree('wt-visible')
-
-    expect(getForegroundTerminalWorktreeIds().sort()).toEqual(['wt-explicit', 'wt-visible'])
-
-    unregister()
-    expect(getForegroundTerminalWorktreeIds()).toEqual(['wt-explicit'])
-  })
-
-  it('keeps duplicate visible worktree claims until every token unregisters', () => {
-    const unregisterFirst = registerVisibleTerminalWorktree('wt-visible')
-    const unregisterSecond = registerVisibleTerminalWorktree('wt-visible')
-
-    expect(getForegroundTerminalWorktreeIds()).toEqual(['wt-visible'])
-
-    unregisterFirst()
-    expect(getForegroundTerminalWorktreeIds()).toEqual(['wt-visible'])
-
-    unregisterSecond()
-    expect(getForegroundTerminalWorktreeIds()).toEqual([])
-  })
-})
diff --git a/src/renderer/src/lib/foreground-terminal-worktrees.ts b/src/renderer/src/lib/foreground-terminal-worktrees.ts
deleted file mode 100644
index 338ec55ba..000000000
--- a/src/renderer/src/lib/foreground-terminal-worktrees.ts
+++ /dev/null
@@ -1,45 +0,0 @@
-let explicitForegroundWorktreeIds = new Set<string>()
-const visibleTerminalClaimsByToken = new Map<symbol, string>()
-
-function normalizeWorktreeIds(worktreeIds: Iterable<string | null | undefined>): Set<string> {
-  return new Set(
-    Array.from(worktreeIds).filter(
-      (worktreeId): worktreeId is string => typeof worktreeId === 'string' && worktreeId.length > 0
-    )
-  )
-}
-
-export function setForegroundTerminalWorktreeIds(
-  worktreeIds: Iterable<string | null | undefined>
-): void {
-  explicitForegroundWorktreeIds = normalizeWorktreeIds(worktreeIds)
-}
-
-export function registerVisibleTerminalWorktree(worktreeId: string | null | undefined): () => void {
-  const normalized = normalizeWorktreeIds([worktreeId])
-  const id = Array.from(normalized)[0]
-  if (!id) {
-    return () => {}
-  }
-
-  // Why: multiple visible panes can belong to one worktree; tokenized claims
-  // let each pane clean up without dropping sibling foreground protection.
-  const token = Symbol(id)
-  visibleTerminalClaimsByToken.set(token, id)
-  return () => {
-    visibleTerminalClaimsByToken.delete(token)
-  }
-}
-
-export function getForegroundTerminalWorktreeIds(): string[] {
-  // Why: hibernation already gates by foreground worktree, so visible pane
-  // claims join the page-level foreground set instead of adding pane rules.
-  return Array.from(
-    new Set([...explicitForegroundWorktreeIds, ...visibleTerminalClaimsByToken.values()])
-  )
-}
-
-export function resetForegroundTerminalWorktreeIdsForTests(): void {
-  explicitForegroundWorktreeIds = new Set()
-  visibleTerminalClaimsByToken.clear()
-}