diff --git a/src/renderer/src/hooks/direct-ssh-host-hydration.test.ts b/src/renderer/src/hooks/direct-ssh-host-hydration.test.ts
index 71d29e256e6..3f8a00813eb 100644
--- a/src/renderer/src/hooks/direct-ssh-host-hydration.test.ts
+++ b/src/renderer/src/hooks/direct-ssh-host-hydration.test.ts
@@ -3,7 +3,7 @@ import { afterEach, describe, expect, it, vi } from 'vitest'
 import type { HostLineageSnapshot } from '../../../shared/host-lineage-contract'
 import type { HostRepoCatalogSnapshot } from '../../../shared/host-repo-catalog-contract'
 import type { DirectSshAuthority, SshProviderEpoch } from '../../../shared/ssh-types'
-import type { Repo } from '../../../shared/types'
+import type { Repo, WorktreeLineage, WorkspaceLineage } from '../../../shared/types'
 import { folderWorkspaceKey, worktreeWorkspaceKey } from '../../../shared/workspace-scope'
 import type { AppState } from '../store/types'
 import { createDirectSshHostHydration } from './direct-ssh-host-hydration'
@@ -40,6 +40,34 @@ function state(overrides: Record<string, unknown> = {}): AppState {
   } as unknown as AppState
 }
 
+function productionLineage(worktreeId: string, parentWorktreeId: string): WorktreeLineage {
+  return {
+    worktreeId,
+    worktreeInstanceId: `${worktreeId}-instance`,
+    parentWorktreeId,
+    parentWorktreeInstanceId: `${parentWorktreeId}-instance`,
+    origin: 'orchestration',
+    capture: { source: 'orchestration-context', confidence: 'explicit' },
+    taskId: 'task-1',
+    coordinatorHandle: 'coord-1',
+    createdAt: 1
+  }
+}
+
+function productionWorkspaceLineage(childId: string, parentId: string): WorkspaceLineage {
+  return {
+    childWorkspaceKey: worktreeWorkspaceKey(childId),
+    childInstanceId: `${childId}-instance`,
+    parentWorkspaceKey: worktreeWorkspaceKey(parentId),
+    parentInstanceId: `${parentId}-instance`,
+    origin: 'orchestration',
+    capture: { source: 'orchestration-context', confidence: 'explicit' },
+    taskId: 'task-1',
+    coordinatorHandle: 'coord-1',
+    createdAt: 1
+  }
+}
+
 function hostSnapshot(
   owner: DirectSshAuthority,
   repos: ReturnType<typeof repo>[]
@@ -341,6 +369,79 @@ describe('createDirectSshHostHydration', () => {
     })
   })
 
+  it('keeps lineage map identity for a cloned no-op host snapshot', async () => {
+    const owner = authority()
+    const hostLineage = productionLineage('a::/work', 'a::/parent')
+    const foreignLineage = productionLineage('b::/work', 'b::/parent')
+    const hostWorkspace = productionWorkspaceLineage('a::/work', 'a::/parent')
+    const foreignWorkspace = productionWorkspaceLineage('b::/work', 'b::/parent')
+    const store = createStore<AppState>(() =>
+      state({
+        repos: [repo('a', 'target-a'), repo('b', 'target-b')],
+        worktreesByRepo: {
+          a: [{ id: 'a::/work', repoId: 'a', hostId: 'ssh:target-a' }],
+          b: [{ id: 'b::/work', repoId: 'b', hostId: 'ssh:target-b' }]
+        },
+        worktreeLineageById: {
+          'a::/work': hostLineage,
+          'b::/work': foreignLineage
+        },
+        workspaceLineageByChildKey: {
+          [worktreeWorkspaceKey('a::/work')]: hostWorkspace,
+          [worktreeWorkspaceKey('b::/work')]: foreignWorkspace
+        }
+      })
+    )
+    const snapshot: HostLineageSnapshot = {
+      authoritative: true,
+      authority: {
+        kind: 'direct-ssh',
+        executionHostId: 'ssh:target-a',
+        ...owner
+      },
+      worktreeLineageById: {
+        'a::/work': hostLineage
+      },
+      workspaceLineageByChildKey: {
+        [worktreeWorkspaceKey('a::/work')]: hostWorkspace
+      }
+    }
+    let publications = 0
+    store.subscribe(() => {
+      publications += 1
+    })
+    const hydration = createDirectSshHostHydration({
+      store,
+      listRepos: vi.fn(),
+      listLineage: vi.fn(async () => structuredClone(snapshot)),
+      isCurrentAuthority: () => true
+    })
+    const beforeLineage = store.getState().worktreeLineageById
+    const beforeWorkspace = store.getState().workspaceLineageByChildKey
+
+    await expect(
+      hydration.readHostScopedLineage({
+        ...owner,
+        catalogRevision: 0,
+        repoRefs: [{ repoId: 'a', executionHostId: 'ssh:target-a' }],
+        authorityRequirement: 'required',
+        reason: 'reconnect'
+      })
+    ).resolves.toBe('complete')
+
+    expect(store.getState().worktreeLineageById).toBe(beforeLineage)
+    expect(store.getState().workspaceLineageByChildKey).toBe(beforeWorkspace)
+    expect(store.getState().worktreeLineageById['a::/work']).toBe(hostLineage)
+    expect(store.getState().worktreeLineageById['b::/work']).toBe(foreignLineage)
+    expect(store.getState().workspaceLineageByChildKey[worktreeWorkspaceKey('a::/work')]).toBe(
+      hostWorkspace
+    )
+    expect(store.getState().workspaceLineageByChildKey[worktreeWorkspaceKey('b::/work')]).toBe(
+      foreignWorkspace
+    )
+    expect(publications).toBe(0)
+  })
+
   it('rejects lineage captured before a newer same-authority catalog revision', async () => {
     const owner = authority()
     const store = createStore<AppState>(() =>
diff --git a/src/renderer/src/hooks/direct-ssh-host-hydration.ts b/src/renderer/src/hooks/direct-ssh-host-hydration.ts
index d3a5a2bc366..069b3b3d323 100644
--- a/src/renderer/src/hooks/direct-ssh-host-hydration.ts
+++ b/src/renderer/src/hooks/direct-ssh-host-hydration.ts
@@ -5,6 +5,7 @@ import type { HostRepoCatalogSnapshot } from '../../../shared/host-repo-catalog-
 import type { DirectSshAuthority } from '../../../shared/ssh-types'
 import { isWorkspaceKey } from '../../../shared/workspace-scope'
 import type { AppState } from '../store/types'
+import { reuseEqualRecordMap } from '../store/slices/repo-identity-reconcile'
 import type {
   DirectSshLineageOutcome,
   DirectSshPreparationInput,
@@ -71,6 +72,20 @@ function mergeExactHostCatalog(state: AppState, snapshot: HostRepoCatalogSnapsho
   }
 }
 
+// Why: the host owns every in-scope key, so drop the stale in-scope rows, overlay the snapshot's,
+// and leave out-of-scope hosts alone. Reusing equal rows keeps a cloned no-op read from republishing.
+function overlayHostScopedLineage<T>(
+  previous: Readonly<Record<string, T>>,
+  incoming: Readonly<Record<string, T>>,
+  isHostScoped: (key: string) => boolean
+): Readonly<Record<string, T>> {
+  const next: Record<string, T> = Object.fromEntries([
+    ...Object.entries(previous).filter(([key]) => !isHostScoped(key)),
+    ...Object.entries(incoming).filter(([key]) => isHostScoped(key))
+  ])
+  return reuseEqualRecordMap(previous, next)
+}
+
 function mergeExactHostLineage(
   state: AppState,
   snapshot: Extract<HostLineageSnapshot, { authoritative: true }>,
@@ -78,38 +93,23 @@ function mergeExactHostLineage(
   catalogRevision: number
 ): AppState {
   const scope = directSshHostHydrationScope(state, authority, catalogRevision)
-  const worktreeLineageById = Object.fromEntries(
-    Object.entries(state.worktreeLineageById).filter(
-      ([worktreeId]) => !scope.gitWorktreeIds.has(worktreeId)
-    )
+  const worktreeLineageById = overlayHostScopedLineage(
+    state.worktreeLineageById,
+    snapshot.worktreeLineageById,
+    (worktreeId) => scope.gitWorktreeIds.has(worktreeId)
   )
-  const workspaceLineageByChildKey = Object.fromEntries(
-    Object.entries(state.workspaceLineageByChildKey).filter(
-      ([childKey]) => !isWorkspaceKey(childKey) || !scope.lineageWorkspaceKeys.has(childKey)
-    )
+  const workspaceLineageByChildKey = overlayHostScopedLineage(
+    state.workspaceLineageByChildKey,
+    snapshot.workspaceLineageByChildKey,
+    (childKey) => isWorkspaceKey(childKey) && scope.lineageWorkspaceKeys.has(childKey)
   )
-  const incomingWorktreeLineage = Object.fromEntries(
-    Object.entries(snapshot.worktreeLineageById).filter(([worktreeId]) =>
-      scope.gitWorktreeIds.has(worktreeId)
-    )
-  )
-  const incomingWorkspaceLineage = Object.fromEntries(
-    Object.entries(snapshot.workspaceLineageByChildKey).filter(
-      ([workspaceKey]) =>
-        isWorkspaceKey(workspaceKey) && scope.lineageWorkspaceKeys.has(workspaceKey)
-    )
-  )
-  return {
-    ...state,
-    worktreeLineageById: {
-      ...worktreeLineageById,
-      ...incomingWorktreeLineage
-    },
-    workspaceLineageByChildKey: {
-      ...workspaceLineageByChildKey,
-      ...incomingWorkspaceLineage
-    }
+  if (
+    worktreeLineageById === state.worktreeLineageById &&
+    workspaceLineageByChildKey === state.workspaceLineageByChildKey
+  ) {
+    return state
   }
+  return { ...state, worktreeLineageById, workspaceLineageByChildKey }
 }
 
 export function createDirectSshHostHydration(
diff --git a/src/renderer/src/store/slices/repo-identity-reconcile.test.ts b/src/renderer/src/store/slices/repo-identity-reconcile.test.ts
index dda221e18b0..ecc1fa7d59e 100644
--- a/src/renderer/src/store/slices/repo-identity-reconcile.test.ts
+++ b/src/renderer/src/store/slices/repo-identity-reconcile.test.ts
@@ -1,7 +1,7 @@
 import { describe, expect, it } from 'vitest'
 import fs from 'node:fs'
 import type { Repo } from '../../../../shared/types'
-import { reconcileFetchedRepos } from './repo-identity-reconcile'
+import { reconcileFetchedRepos, reuseEqualRecordMap } from './repo-identity-reconcile'
 
 function makeRepo(id: string, overrides: Partial<Repo> = {}): Repo {
   return { id, path: `/${id}`, displayName: id, badgeColor: '#000', addedAt: 1, ...overrides }
@@ -123,3 +123,54 @@ describe('reconcileFetchedRepos', () => {
     expect(source).not.toMatch(/previous\.find|next\.find|findIndex/)
   })
 })
+
+describe('reuseEqualRecordMap', () => {
+  const row = (value: string): { value: string; nested: { tags: string[] } } => ({
+    value,
+    nested: { tags: [value, 'shared'] }
+  })
+
+  it('returns the previous map when every key holds an equal value', () => {
+    const previous = { a: row('a'), b: row('b') }
+    expect(reuseEqualRecordMap(previous, { a: row('a'), b: row('b') })).toBe(previous)
+  })
+
+  it('reuses the previous entry for structurally equal nested values', () => {
+    const previous = { a: row('a'), b: row('b') }
+    const result = reuseEqualRecordMap(previous, { a: row('a'), b: row('changed') })
+    expect(result).not.toBe(previous)
+    expect(result.a).toBe(previous.a)
+    expect(result.b).toEqual(row('changed'))
+  })
+
+  it('returns a new map when a value changed', () => {
+    const previous = { a: row('a') }
+    const result = reuseEqualRecordMap(previous, { a: row('changed') })
+    expect(result).not.toBe(previous)
+    expect(result.a).toEqual(row('changed'))
+  })
+
+  it('returns a new map when a key is added', () => {
+    const previous = { a: row('a') }
+    const result = reuseEqualRecordMap(previous, { a: row('a'), b: row('b') })
+    expect(result).not.toBe(previous)
+    expect(result.a).toBe(previous.a)
+    expect(Object.keys(result)).toEqual(['a', 'b'])
+  })
+
+  it('returns a new map when a key is removed', () => {
+    const previous = { a: row('a'), b: row('b') }
+    const result = reuseEqualRecordMap(previous, { a: row('a') })
+    expect(result).not.toBe(previous)
+    expect(Object.keys(result)).toEqual(['a'])
+  })
+
+  it('returns a new map when a key is swapped for a same-count replacement', () => {
+    // Why: equal key counts alone must not read as unchanged — the replacement key misses the
+    // previous lookup, which is why no second pass over the previous keys is needed.
+    const previous = { a: row('a'), b: row('b') }
+    const result = reuseEqualRecordMap(previous, { a: row('a'), c: row('b') })
+    expect(result).not.toBe(previous)
+    expect(Object.keys(result)).toEqual(['a', 'c'])
+  })
+})
diff --git a/src/renderer/src/store/slices/repo-identity-reconcile.ts b/src/renderer/src/store/slices/repo-identity-reconcile.ts
index f61107c2673..db59e619d97 100644
--- a/src/renderer/src/store/slices/repo-identity-reconcile.ts
+++ b/src/renderer/src/store/slices/repo-identity-reconcile.ts
@@ -79,3 +79,28 @@ export function reconcileFetchedRepos(
 ): readonly Repo[] {
   return reconcileCatalogRows(previous, next, getRepoHostIdentity)
 }
+
+/**
+ * Reuses equal record values from `previous` — and the whole map when nothing
+ * changed — so a cloned no-op refresh leaves Object.is subscribers untouched.
+ */
+export function reuseEqualRecordMap<T>(
+  previous: Readonly<Record<string, T>>,
+  next: Readonly<Record<string, T>>
+): Readonly<Record<string, T>> {
+  const nextKeys = Object.keys(next)
+  // Why: a matching key count plus every `next` key resolving to an equal `previous` entry below
+  // means the key sets match, so a removed key always lands as either a count or a lookup miss.
+  let identical = nextKeys.length === Object.keys(previous).length
+  const reconciled: Record<string, T> = {}
+  for (const key of nextKeys) {
+    const existing = Object.hasOwn(previous, key) ? previous[key] : undefined
+    if (existing !== undefined && areValuesEqual(existing, next[key])) {
+      reconciled[key] = existing
+      continue
+    }
+    identical = false
+    reconciled[key] = next[key]
+  }
+  return identical ? previous : reconciled
+}
diff --git a/src/renderer/src/store/slices/worktree-helpers.ts b/src/renderer/src/store/slices/worktree-helpers.ts
index 9675be9a693..c2980357ee8 100644
--- a/src/renderer/src/store/slices/worktree-helpers.ts
+++ b/src/renderer/src/store/slices/worktree-helpers.ts
@@ -89,8 +89,8 @@ export type ActiveWorktreeStateTransition = (state: AppState) => {
 export type WorktreeSlice = {
   worktreesByRepo: Record<string, Worktree[]>
   detectedWorktreesByRepo: Record<string, DetectedWorktreeListResult>
-  worktreeLineageById: Record<string, WorktreeLineage>
-  workspaceLineageByChildKey: Record<WorkspaceKey, WorkspaceLineage>
+  worktreeLineageById: Readonly<Record<string, WorktreeLineage>>
+  workspaceLineageByChildKey: Readonly<Record<WorkspaceKey, WorkspaceLineage>>
   activeWorktreeId: string | null
   activeWorkspaceKey: WorkspaceKey | null
   activeWorkspaceExecutionHostId: ExecutionHostId | null
diff --git a/src/renderer/src/store/slices/worktrees.test.ts b/src/renderer/src/store/slices/worktrees.test.ts
index 5ebe9a06116..6077204ba51 100644
--- a/src/renderer/src/store/slices/worktrees.test.ts
+++ b/src/renderer/src/store/slices/worktrees.test.ts
@@ -3187,6 +3187,71 @@ describe('fetchWorktrees', () => {
     expect(store.getState().sortEpoch).toBe(7)
   })
 
+  it('keeps remote lineage map identity when a cloned payload is unchanged', async () => {
+    const store = createTestStore()
+    const worktree = makeWorktree({
+      id: 'repo1::/remote/wt1',
+      repoId: 'repo1',
+      path: '/remote/wt1',
+      branch: 'refs/heads/remote',
+      hostId: 'runtime:env-1'
+    })
+    const lineage = makeLineage({
+      worktreeId: worktree.id,
+      parentWorktreeId: 'repo1::/remote/parent',
+      capture: { source: 'orchestration-context', confidence: 'explicit' },
+      taskId: 'task-42',
+      coordinatorHandle: 'coord-1'
+    })
+    const workspaceLineage = makeWorkspaceLineage({
+      childWorkspaceKey: worktreeWorkspaceKey(worktree.id),
+      parentWorkspaceKey: worktreeWorkspaceKey(lineage.parentWorktreeId),
+      childInstanceId: lineage.worktreeInstanceId,
+      parentInstanceId: lineage.parentWorktreeInstanceId,
+      origin: lineage.origin,
+      capture: lineage.capture,
+      taskId: lineage.taskId,
+      coordinatorHandle: lineage.coordinatorHandle,
+      createdAt: lineage.createdAt
+    })
+    const detected = makeDetectedResult('repo1', [worktree])
+    store.setState({
+      settings: { activeRuntimeEnvironmentId: 'env-1' } as never,
+      worktreesByRepo: { repo1: [worktree] },
+      detectedWorktreesByRepo: { repo1: detected },
+      worktreeLineageById: { [lineage.worktreeId]: lineage },
+      workspaceLineageByChildKey: {
+        [workspaceLineage.childWorkspaceKey]: workspaceLineage
+      },
+      sortEpoch: 7
+    } as Partial<AppState>)
+    runtimeEnvironmentCall.mockImplementation(({ method }: RuntimeEnvironmentCallRequest) => {
+      const result =
+        method === 'worktree.lineageList'
+          ? structuredClone({
+              lineage: { [lineage.worktreeId]: lineage },
+              workspaceLineage: { [workspaceLineage.childWorkspaceKey]: workspaceLineage }
+            })
+          : structuredClone(detected)
+      return Promise.resolve({
+        id: 'rpc-1',
+        ok: true,
+        result,
+        _meta: { runtimeId: 'runtime-remote' }
+      })
+    })
+    const before = store.getState()
+
+    await store.getState().fetchWorktrees('repo1')
+
+    expect(store.getState().worktreeLineageById).toBe(before.worktreeLineageById)
+    expect(store.getState().workspaceLineageByChildKey).toBe(before.workspaceLineageByChildKey)
+    expect(store.getState().worktreeLineageById[lineage.worktreeId]).toBe(lineage)
+    expect(store.getState().workspaceLineageByChildKey[workspaceLineage.childWorkspaceKey]).toBe(
+      workspaceLineage
+    )
+  })
+
   it('defers remote lineage when a caller owns the final host refresh', async () => {
     const store = createTestStore()
     const worktree = makeWorktree({
@@ -3319,6 +3384,135 @@ describe('worktree lineage state', () => {
     })
   })
 
+  it('keeps lineage map and entry identity across a cloned no-op refresh', async () => {
+    const lineage = makeLineage({
+      capture: { source: 'orchestration-context', confidence: 'explicit' },
+      taskId: 'task-42',
+      coordinatorHandle: 'coord-1'
+    })
+    const workspaceLineage = makeWorkspaceLineage({
+      childWorkspaceKey: worktreeWorkspaceKey(lineage.worktreeId),
+      parentWorkspaceKey: worktreeWorkspaceKey(lineage.parentWorktreeId),
+      childInstanceId: lineage.worktreeInstanceId,
+      parentInstanceId: lineage.parentWorktreeInstanceId,
+      origin: lineage.origin,
+      capture: lineage.capture,
+      taskId: lineage.taskId,
+      coordinatorHandle: lineage.coordinatorHandle,
+      createdAt: lineage.createdAt
+    })
+    const store = createLocalLineageTestStore(lineage)
+    const payload = {
+      lineage: { [lineage.worktreeId]: lineage },
+      workspaceLineage: { [workspaceLineage.childWorkspaceKey]: workspaceLineage }
+    }
+    mockApi.worktrees.listLineage.mockImplementation(async () => structuredClone(payload))
+
+    await store.getState().fetchWorktreeLineage()
+    const afterFirst = store.getState()
+    const lineageById = afterFirst.worktreeLineageById
+    const workspaceByKey = afterFirst.workspaceLineageByChildKey
+    const lineageEntry = lineageById[lineage.worktreeId]
+    const workspaceEntry = workspaceByKey[workspaceLineage.childWorkspaceKey]
+    expect(lineageEntry).toEqual(lineage)
+    expect(lineageEntry).not.toBe(lineage)
+    const subscriber = vi.fn()
+    const unsubscribe = store.subscribe(subscriber)
+
+    await store.getState().fetchWorktreeLineage()
+    unsubscribe()
+
+    expect(store.getState().worktreeLineageById).toBe(lineageById)
+    expect(store.getState().workspaceLineageByChildKey).toBe(workspaceByKey)
+    expect(store.getState().worktreeLineageById[lineage.worktreeId]).toBe(lineageEntry)
+    expect(store.getState().workspaceLineageByChildKey[workspaceLineage.childWorkspaceKey]).toBe(
+      workspaceEntry
+    )
+    expect(subscriber).not.toHaveBeenCalled()
+    expect(mockApi.worktrees.listLineage).toHaveBeenCalledTimes(2)
+  })
+
+  it('preserves other-host lineage row identity across a cloned same-host refresh', async () => {
+    const store = createTestStore()
+    const localWorktree = makeWorktree({
+      id: 'repo1::/local/child',
+      repoId: 'repo1',
+      hostId: LOCAL_EXECUTION_HOST_ID
+    })
+    const sshWorktree = makeWorktree({
+      id: 'repo2::/ssh/child',
+      repoId: 'repo2',
+      hostId: 'ssh:ssh-1'
+    })
+    const localLineage = makeLineage({
+      worktreeId: localWorktree.id,
+      parentWorktreeId: 'repo1::/local/parent',
+      capture: { source: 'orchestration-context', confidence: 'explicit' },
+      taskId: 'task-local',
+      coordinatorHandle: 'coord-local'
+    })
+    const sshLineage = makeLineage({
+      worktreeId: sshWorktree.id,
+      parentWorktreeId: 'repo2::/ssh/parent',
+      capture: { source: 'cwd-context', confidence: 'inferred' },
+      taskId: 'task-ssh',
+      coordinatorHandle: 'coord-ssh'
+    })
+    const localWorkspace = makeWorkspaceLineage({
+      childWorkspaceKey: worktreeWorkspaceKey(localWorktree.id),
+      parentWorkspaceKey: worktreeWorkspaceKey(localLineage.parentWorktreeId),
+      childInstanceId: localLineage.worktreeInstanceId,
+      parentInstanceId: localLineage.parentWorktreeInstanceId,
+      origin: localLineage.origin,
+      capture: localLineage.capture,
+      taskId: localLineage.taskId,
+      coordinatorHandle: localLineage.coordinatorHandle
+    })
+    const sshWorkspace = makeWorkspaceLineage({
+      childWorkspaceKey: worktreeWorkspaceKey(sshWorktree.id),
+      parentWorkspaceKey: worktreeWorkspaceKey(sshLineage.parentWorktreeId),
+      childInstanceId: sshLineage.worktreeInstanceId,
+      parentInstanceId: sshLineage.parentWorktreeInstanceId,
+      origin: sshLineage.origin,
+      capture: sshLineage.capture,
+      taskId: sshLineage.taskId,
+      coordinatorHandle: sshLineage.coordinatorHandle
+    })
+    store.setState({
+      worktreesByRepo: {
+        repo1: [localWorktree],
+        repo2: [sshWorktree]
+      },
+      worktreeLineageById: {
+        [localWorktree.id]: localLineage,
+        [sshWorktree.id]: sshLineage
+      },
+      workspaceLineageByChildKey: {
+        [localWorkspace.childWorkspaceKey]: localWorkspace,
+        [sshWorkspace.childWorkspaceKey]: sshWorkspace
+      }
+    } as Partial<AppState>)
+    const payload = {
+      lineage: { [localWorktree.id]: localLineage },
+      workspaceLineage: { [localWorkspace.childWorkspaceKey]: localWorkspace }
+    }
+    mockApi.worktrees.listLineage.mockImplementation(async () => structuredClone(payload))
+    const before = store.getState()
+
+    await store.getState().fetchWorktreeLineage()
+
+    expect(store.getState().worktreeLineageById).toBe(before.worktreeLineageById)
+    expect(store.getState().workspaceLineageByChildKey).toBe(before.workspaceLineageByChildKey)
+    expect(store.getState().worktreeLineageById[localWorktree.id]).toBe(localLineage)
+    expect(store.getState().worktreeLineageById[sshWorktree.id]).toBe(sshLineage)
+    expect(store.getState().workspaceLineageByChildKey[localWorkspace.childWorkspaceKey]).toBe(
+      localWorkspace
+    )
+    expect(store.getState().workspaceLineageByChildKey[sshWorkspace.childWorkspaceKey]).toBe(
+      sshWorkspace
+    )
+  })
+
   it('clears workspace lineage on successful old-shape lineage refresh', async () => {
     const store = createTestStore()
     const lineage = makeLineage()
diff --git a/src/renderer/src/store/slices/worktrees.ts b/src/renderer/src/store/slices/worktrees.ts
index 9c1fc6691ec..00e421cb7df 100644
--- a/src/renderer/src/store/slices/worktrees.ts
+++ b/src/renderer/src/store/slices/worktrees.ts
@@ -133,6 +133,7 @@ import type {
 import type { DirectSshAuthority } from '../../../../shared/ssh-types'
 import { findIndexedWorktreeOwnerForHost } from '@/lib/worktree-runtime-owner-index'
 import { catalogRowsEqual, reuseEqualCatalogRows } from './worktree-catalog-reconciliation'
+import { reuseEqualRecordMap } from './repo-identity-reconcile'
 export type { WorktreeSlice, WorktreeDeleteState } from './worktree-helpers'
 
 // Why: old runtime servers only have `worktree.list`; preserve the large-list UI hydration parity used before `worktree.detectedList` existed.
@@ -1390,8 +1391,8 @@ async function listWorktreeLineageForRuntime(
   settings: AppState['settings'],
   options: BackgroundRuntimeRefreshOptions = {}
 ): Promise<{
-  worktreeLineageById: Record<string, WorktreeLineage>
-  workspaceLineageByChildKey: Record<string, WorkspaceLineage>
+  worktreeLineageById: Readonly<Record<string, WorktreeLineage>>
+  workspaceLineageByChildKey: Readonly<Record<string, WorkspaceLineage>>
 }> {
   const target = getActiveRuntimeTarget(settings)
   type LineageListResponse = {
@@ -1570,21 +1571,38 @@ function applyWorktreeLineageUpdate(
   })
 }
 
+function applyHostLineageRefresh(
+  set: Parameters<StateCreator<AppState>>[0],
+  hostId: ExecutionHostId,
+  lineage: {
+    worktreeLineageById: Readonly<Record<string, WorktreeLineage>>
+    workspaceLineageByChildKey: Readonly<Record<string, WorkspaceLineage>>
+  }
+): void {
+  set((s) => {
+    const worktreeLineageById = mergeLineageForHost(s, hostId, lineage.worktreeLineageById)
+    const workspaceLineageByChildKey = mergeWorkspaceLineageForHost(
+      s,
+      hostId,
+      lineage.workspaceLineageByChildKey
+    )
+    if (
+      worktreeLineageById === s.worktreeLineageById &&
+      workspaceLineageByChildKey === s.workspaceLineageByChildKey
+    ) {
+      return s
+    }
+    return { worktreeLineageById, workspaceLineageByChildKey }
+  })
+}
+
 async function refreshWorktreeLineageForSettings(
   settings: AppState['settings'],
   set: Parameters<StateCreator<AppState>>[0],
   options: BackgroundRuntimeRefreshOptions = {}
 ): Promise<void> {
   const lineage = await listWorktreeLineageForRuntime(settings, options)
-  const hostId = getSettingsFocusedExecutionHostId(settings)
-  set((s) => ({
-    worktreeLineageById: mergeLineageForHost(s, hostId, lineage.worktreeLineageById),
-    workspaceLineageByChildKey: mergeWorkspaceLineageForHost(
-      s,
-      hostId,
-      lineage.workspaceLineageByChildKey
-    )
-  }))
+  applyHostLineageRefresh(set, getSettingsFocusedExecutionHostId(settings), lineage)
 }
 
 async function refreshRemoteWorktreeLineageBestEffort(
@@ -1598,15 +1616,7 @@ async function refreshRemoteWorktreeLineageBestEffort(
     const lineage = await listWorktreeLineageForRuntime(settings, {
       reuseRecentCompatibilityFailure: true
     })
-    const hostId = getSettingsFocusedExecutionHostId(settings)
-    set((s) => ({
-      worktreeLineageById: mergeLineageForHost(s, hostId, lineage.worktreeLineageById),
-      workspaceLineageByChildKey: mergeWorkspaceLineageForHost(
-        s,
-        hostId,
-        lineage.workspaceLineageByChildKey
-      )
-    }))
+    applyHostLineageRefresh(set, getSettingsFocusedExecutionHostId(settings), lineage)
   } catch (err) {
     // Why: lineage is supplemental, so a remote timeout here must not discard a successful worktree refresh.
     console.error('Failed to fetch worktree lineage:', err)
@@ -1638,15 +1648,18 @@ function mergeLineageForHost(
     'repos' | 'settings' | 'worktreesByRepo' | 'detectedWorktreesByRepo' | 'worktreeLineageById'
   >,
   hostId: ExecutionHostId,
-  lineage: Record<string, WorktreeLineage>
-): Record<string, WorktreeLineage> {
+  lineage: Readonly<Record<string, WorktreeLineage>>
+): Readonly<Record<string, WorktreeLineage>> {
   const next: Record<string, WorktreeLineage> = {}
   for (const [worktreeId, existing] of Object.entries(state.worktreeLineageById)) {
     if (getWorktreeHostId(state, worktreeId) !== hostId) {
       next[worktreeId] = existing
     }
   }
-  return { ...next, ...lineage }
+  for (const [worktreeId, incoming] of Object.entries(lineage)) {
+    next[worktreeId] = incoming
+  }
+  return reuseEqualRecordMap(state.worktreeLineageById, next)
 }
 
 function mergeWorkspaceLineageForHost(
@@ -1659,8 +1672,8 @@ function mergeWorkspaceLineageForHost(
     | 'workspaceLineageByChildKey'
   >,
   hostId: ExecutionHostId,
-  lineage: Record<string, WorkspaceLineage>
-): Record<string, WorkspaceLineage> {
+  lineage: Readonly<Record<string, WorkspaceLineage>>
+): Readonly<Record<string, WorkspaceLineage>> {
   const next: Record<string, WorkspaceLineage> = {}
   for (const [childKey, existing] of Object.entries(state.workspaceLineageByChildKey)) {
     const childScope = parseWorkspaceKey(existing.childWorkspaceKey)
@@ -1671,7 +1684,10 @@ function mergeWorkspaceLineageForHost(
       next[childKey] = existing
     }
   }
-  return { ...next, ...lineage }
+  for (const [childKey, incoming] of Object.entries(lineage)) {
+    next[childKey] = incoming
+  }
+  return reuseEqualRecordMap(state.workspaceLineageByChildKey, next)
 }
 
 async function persistWorktreeMeta(