Improve perf hot paths

Deduplicate watcher cleanup, reduce redundant terminal capture/diagnostics, bound remote terminal snapshot replay memory, and suppress redundant git/upstream status work.

src/main/ipc/filesystem-watcher.test.ts

@@ -194,4 +194,37 @@ describe('registerFilesystemWatcherHandlers', () => {
     )
     expect(unwatchMock).toHaveBeenCalledTimes(1)
   })
+
+  it('registers one destroyed listener for many SSH worktree watches', async () => {
+    const destroyedCallbacks: (() => void)[] = []
+    const sender = {
+      isDestroyed: () => false,
+      send: vi.fn(),
+      once: vi.fn((event: string, callback: () => void) => {
+        if (event === 'destroyed') {
+          destroyedCallbacks.push(callback)
+        }
+      }),
+      id: 99
+    }
+    const unwatchMock = vi.fn()
+    const watchMock = vi.fn().mockResolvedValue(unwatchMock)
+    getSshFilesystemProviderMock.mockReturnValue({ watch: watchMock })
+
+    for (let i = 0; i < 12; i += 1) {
+      await handlers['fs:watchWorktree'](
+        { sender },
+        { worktreePath: `/home/me/repo-${i}`, connectionId: 'conn-1' }
+      )
+    }
+
+    // Why: WebContents warns after 10 listeners. The cleanup work still covers
+    // every remote watch by scanning the shared remote watcher registry.
+    expect(sender.once).toHaveBeenCalledTimes(1)
+    expect(destroyedCallbacks).toHaveLength(1)
+
+    destroyedCallbacks[0]()
+
+    expect(unwatchMock).toHaveBeenCalledTimes(12)
+  })
 })

src/main/ipc/filesystem-watcher.ts

@@ -50,10 +50,9 @@ const watchedRoots = new Map<string, WatchedRoot>()
 // repeated "Failed to read changes" / "watchman not found" errors.
 const unwatchableRoots = new Set<string>()
 
-// Why: the `destroyed` listener was previously registered per-root on the
-// same WebContents.  With 11+ worktrees, this exceeded Node's default
-// MaxListeners of 10.  Track which senders already have a single cleanup
-// listener so we register exactly once per sender.
+// Why: watcher cleanup is keyed to the renderer WebContents, not to a specific
+// watched root. One listener per sender avoids MaxListeners warnings when a
+// workspace has many local and SSH-backed worktrees open.
 const senderCleanupRegistered = new Set<number>()
 
 // Why: on Windows, tearing down and recreating @parcel/watcher subscriptions
@@ -311,6 +310,41 @@ async function createWatcher(rootKey: string, rootPath: string): Promise<Watched
 
 // ── Subscribe / Unsubscribe ──────────────────────────────────────────
 
+function cleanupLocalWatchersForSender(senderId: number): void {
+  for (const [key, watchedRoot] of watchedRoots) {
+    if (watchedRoot.listeners.has(senderId)) {
+      watchedRoot.listeners.delete(senderId)
+      if (watchedRoot.listeners.size === 0) {
+        // Cancel any pending grace-period teardown for this root.
+        const pending = pendingTeardowns.get(key)
+        if (pending) {
+          clearTimeout(pending)
+          pendingTeardowns.delete(key)
+        }
+        if (watchedRoot.batch.timer) {
+          clearTimeout(watchedRoot.batch.timer)
+        }
+        void watchedRoot.subscription.unsubscribe().catch((err: unknown) => {
+          console.error(`[filesystem-watcher] unsubscribe error for ${key}:`, err)
+        })
+        watchedRoots.delete(key)
+      }
+    }
+  }
+}
+
+function registerSenderCleanup(sender: WebContents): void {
+  if (senderCleanupRegistered.has(sender.id)) {
+    return
+  }
+  senderCleanupRegistered.add(sender.id)
+  sender.once('destroyed', () => {
+    senderCleanupRegistered.delete(sender.id)
+    cleanupLocalWatchersForSender(sender.id)
+    cleanupRemoteWatchersForSender(sender.id)
+  })
+}
+
 async function subscribe(worktreePath: string, sender: WebContents): Promise<void> {
   const rootKey = normalizeRootPath(worktreePath)
 
@@ -364,38 +398,7 @@ async function subscribe(worktreePath: string, sender: WebContents): Promise<voi
   }
 
   root.listeners.set(sender.id, sender)
-
-  // Why: register a single `destroyed` listener per sender (not per-root).
-  // The old code registered one listener per root, so 11+ worktrees would
-  // exceed Node's default MaxListeners of 10 on the same WebContents.  A
-  // single listener that iterates all roots avoids the warning and is
-  // equivalent — `destroyed` fires once when the renderer process exits.
-  if (!senderCleanupRegistered.has(sender.id)) {
-    senderCleanupRegistered.add(sender.id)
-    sender.once('destroyed', () => {
-      senderCleanupRegistered.delete(sender.id)
-      for (const [key, watchedRoot] of watchedRoots) {
-        if (watchedRoot.listeners.has(sender.id)) {
-          watchedRoot.listeners.delete(sender.id)
-          if (watchedRoot.listeners.size === 0) {
-            // Cancel any pending grace-period teardown for this root.
-            const pending = pendingTeardowns.get(key)
-            if (pending) {
-              clearTimeout(pending)
-              pendingTeardowns.delete(key)
-            }
-            if (watchedRoot.batch.timer) {
-              clearTimeout(watchedRoot.batch.timer)
-            }
-            void watchedRoot.subscription.unsubscribe().catch((err: unknown) => {
-              console.error(`[filesystem-watcher] unsubscribe error for ${key}:`, err)
-            })
-            watchedRoots.delete(key)
-          }
-        }
-      }
-    })
-  }
+  registerSenderCleanup(sender)
 }
 
 function unsubscribe(worktreePath: string, senderId: number): void {
@@ -455,9 +458,7 @@ function addRemoteWatchListener(key: string, sender: WebContents): void {
     return
   }
   state.listeners.set(sender.id, sender)
-  sender.once('destroyed', () => {
-    releaseRemoteWatchListener(key, sender.id)
-  })
+  registerSenderCleanup(sender)
 }
 
 function releaseRemoteWatchListener(key: string, senderId: number): void {
@@ -473,6 +474,12 @@ function releaseRemoteWatchListener(key: string, senderId: number): void {
   remoteWatchers.delete(key)
 }
 
+function cleanupRemoteWatchersForSender(senderId: number): void {
+  for (const key of Array.from(remoteWatchers.keys())) {
+    releaseRemoteWatchListener(key, senderId)
+  }
+}
+
 type RemoteWatcherInstallResult = 'installed' | 'unavailable' | 'cancelled'
 
 async function installRemoteWatcher(
@@ -637,6 +644,8 @@ export function registerFilesystemWatcherHandlers(): void {
 
 /** Tear down all watchers on app shutdown. */
 export async function closeAllWatchers(): Promise<void> {
+  senderCleanupRegistered.clear()
+
   // Cancel any pending grace-period teardowns — we're tearing down everything.
   for (const timer of pendingTeardowns.values()) {
     clearTimeout(timer)

src/renderer/src/components/right-sidebar/useGitStatusPolling.test.ts

@@ -58,7 +58,8 @@ async function usePollingOnce(
       useEffect: (effect: () => void | (() => void)) => {
         effect()
       },
-      useMemo: (factory: () => unknown) => factory()
+      useMemo: (factory: () => unknown) => factory(),
+      useRef: <T>(initial: T) => ({ current: initial })
     }
   })
 
@@ -159,4 +160,87 @@ describe('useGitStatusPolling', () => {
     expect(gitStatus).not.toHaveBeenCalled()
     expect(state.setGitStatus).not.toHaveBeenCalled()
   })
+
+  it('does not overlap slow git status polls and runs one trailing refresh', async () => {
+    vi.resetModules()
+    let intervalCallback: (() => void) | null = null
+    let resolveFirst!: (value: GitStatusResult) => void
+    const firstStatus = new Promise<GitStatusResult>((resolve) => {
+      resolveFirst = resolve
+    })
+    const state: PollState = {
+      activeWorktreeId: worktree.id,
+      updateWorktreeGitIdentity: vi.fn(),
+      setGitStatus: vi.fn(),
+      fetchUpstreamStatus: vi.fn().mockResolvedValue(undefined),
+      setUpstreamStatus: vi.fn(),
+      setConflictOperation: vi.fn(),
+      gitConflictOperationByWorktree: {},
+      sshConnectionStates: new Map()
+    }
+    const status: GitStatusResult = {
+      entries: [],
+      conflictOperation: 'unknown',
+      head: 'abc123',
+      branch: 'refs/heads/main'
+    }
+    const gitStatus = vi.fn().mockReturnValueOnce(firstStatus).mockResolvedValue(status)
+
+    vi.doMock('react', async () => {
+      const actual = await vi.importActual<typeof React>('react')
+      return {
+        ...actual,
+        useCallback: (callback: unknown) => callback,
+        useEffect: (effect: () => void | (() => void)) => {
+          effect()
+        },
+        useMemo: (factory: () => unknown) => factory(),
+        useRef: <T>(initial: T) => ({ current: initial })
+      }
+    })
+
+    vi.doMock('@/store', () => ({
+      useAppStore: Object.assign((selector: (s: PollState) => unknown) => selector(state), {
+        getState: () => ({ settings: null })
+      })
+    }))
+    vi.doMock('@/store/selectors', () => ({
+      useActiveWorktree: () => worktree,
+      useAllWorktrees: () => [worktree],
+      useRepoById: () => repo,
+      useRepoMap: () => new Map([[repo.id, repo]])
+    }))
+    vi.doMock('@/lib/connection-context', () => ({
+      getConnectionId: () => undefined
+    }))
+
+    vi.stubGlobal('window', {
+      api: { git: { status: gitStatus } },
+      addEventListener: vi.fn(),
+      removeEventListener: vi.fn()
+    })
+    vi.stubGlobal('document', { hasFocus: () => true })
+    vi.stubGlobal(
+      'setInterval',
+      vi.fn((callback: () => void) => {
+        intervalCallback = callback
+        return 1
+      })
+    )
+    vi.stubGlobal('clearInterval', vi.fn())
+
+    const { useGitStatusPolling: runPolling } = await import('./useGitStatusPolling')
+    GitStatusPollingHarness({ runPolling })
+    await vi.waitFor(() => expect(gitStatus).toHaveBeenCalledTimes(1))
+
+    expect(intervalCallback).toBeTypeOf('function')
+    const tick = intervalCallback as unknown as () => void
+    tick()
+    tick()
+    expect(gitStatus).toHaveBeenCalledTimes(1)
+
+    resolveFirst(status)
+    await vi.waitFor(() => expect(gitStatus).toHaveBeenCalledTimes(2))
+    await vi.waitFor(() => expect(state.setGitStatus).toHaveBeenCalledTimes(2))
+  })
 })

src/renderer/src/components/right-sidebar/useGitStatusPolling.ts

@@ -1,4 +1,4 @@
-import { useCallback, useEffect, useMemo } from 'react'
+import { useCallback, useEffect, useMemo, useRef } from 'react'
 import { useAppStore } from '@/store'
 import { useActiveWorktree, useAllWorktrees, useRepoById, useRepoMap } from '@/store/selectors'
 import type { GitConflictOperation } from '../../../../shared/types'
@@ -21,6 +21,9 @@ export function useGitStatusPolling(): void {
   const conflictOperationByWorktree = useAppStore((s) => s.gitConflictOperationByWorktree)
   const sshConnectionStates = useAppStore((s) => s.sshConnectionStates)
   const repoMap = useRepoMap()
+  const statusPollInFlightRef = useRef(false)
+  const statusPollRerunRef = useRef(false)
+  const fetchStatusRef = useRef<() => void>(() => {})
 
   const worktreePath = activeWorktree?.path ?? null
   const activeRepoId = activeWorktree?.repoId ?? null
@@ -55,7 +58,7 @@ export function useGitStatusPolling(): void {
     return result
   }, [allWorktrees, conflictOperationByWorktree, activeWorktreeId, repoMap])
 
-  const fetchStatus = useCallback(async () => {
+  const runFetchStatus = useCallback(async () => {
     if (!activeWorktreeId || !worktreePath || !activeRepoSupportsGit) {
       return
     }
@@ -91,6 +94,25 @@ export function useGitStatusPolling(): void {
     updateWorktreeGitIdentity
   ])
 
+  const fetchStatus = useCallback(() => {
+    if (statusPollInFlightRef.current) {
+      statusPollRerunRef.current = true
+      return
+    }
+    statusPollInFlightRef.current = true
+    // Why: git status can exceed the 3s poll interval on large repos. Keep at
+    // most one subprocess chain in flight, then run one trailing refresh if a
+    // tick was skipped so the UI catches up without process pileups.
+    void runFetchStatus().finally(() => {
+      statusPollInFlightRef.current = false
+      if (statusPollRerunRef.current) {
+        statusPollRerunRef.current = false
+        fetchStatusRef.current()
+      }
+    })
+  }, [runFetchStatus])
+  fetchStatusRef.current = fetchStatus
+
   useEffect(() => {
     void fetchStatus()
     // Why: skip IPC-heavy git status calls when the window is not focused.

src/renderer/src/components/terminal-pane/pty-connection.test.ts

@@ -333,6 +333,26 @@ describe('connectPanePty', () => {
         .cancelAnimationFrame
     }
     delete (globalThis as unknown as { window?: unknown }).window
+    delete (globalThis as Record<string, unknown>).__ptyConnectDiag
+  })
+
+  it('does not retain PTY connect diagnostics unless e2e debug state is enabled', async () => {
+    const { connectPanePty } = await import('./pty-connection')
+    const logSpy = vi.spyOn(console, 'log').mockImplementation(() => {})
+    const transport = createMockTransport()
+    transportFactoryQueue.push(transport)
+    mockStoreState = {
+      ...mockStoreState,
+      tabsByWorktree: { 'wt-1': [{ id: 'tab-1', ptyId: null }] },
+      ptyIdsByTabId: { 'tab-1': [] }
+    }
+
+    connectPanePty(createPane(1) as never, createManager(1) as never, createDeps() as never)
+    await flushAsyncTicks()
+
+    expect((globalThis as Record<string, unknown>).__ptyConnectDiag).toBeUndefined()
+    expect(logSpy).not.toHaveBeenCalledWith(expect.stringContaining('[pty-connect]'))
+    logSpy.mockRestore()
   })
 
   it('does not send startup command via sendInput for local connections', async () => {

src/renderer/src/components/terminal-pane/pty-connection.ts

@@ -26,10 +26,25 @@ import {
 } from '@/lib/pane-manager/pane-terminal-output-scheduler'
 import { makePaneKey } from '../../../../shared/stable-pane-id'
 import { createTerminalCommandLifecycle } from './terminal-command-lifecycle'
+import { e2eConfig } from '@/lib/e2e-config'
 
 const pendingSpawnByPaneKey = new Map<string, Promise<string | null>>()
 const SSH_SESSION_EXPIRED_ERROR = 'SSH_SESSION_EXPIRED'
 const REMOTE_PTY_ID_PREFIX = 'remote:'
+const PTY_CONNECT_DIAG_LIMIT = 200
+
+function recordPtyConnectDiagnostic(message: string): void {
+  if (!e2eConfig.exposeStore) {
+    return
+  }
+  console.log(`[pty-connect] ${message}`)
+  const target = globalThis as Record<string, unknown>
+  const diag = (target.__ptyConnectDiag ??= [] as string[]) as string[]
+  diag.push(message)
+  if (diag.length > PTY_CONNECT_DIAG_LIMIT) {
+    diag.splice(0, diag.length - PTY_CONNECT_DIAG_LIMIT)
+  }
+}
 
 // Why: when multiple panes/tabs need the same deferred SSH connection,
 // the first one calls ssh.connect() and subsequent ones must wait for it
@@ -1086,17 +1101,13 @@ export function connectPanePty(
       isSessionOwnedByWorktree(candidateReattachSessionId, deps.worktreeId)
         ? candidateReattachSessionId
         : null
-    const _diagMsg = `pane=${pane.id} tab=${deps.tabId} restored=${restoredPtyId} existing=${existingPtyId} detached=${detachedLivePtyId} reattach=${deferredReattachSessionId} hasTransport=${hasExistingPaneTransport} pendingKey=${pendingSpawnKey}`
-    console.log(`[pty-connect] ${_diagMsg}`)
-    ;((globalThis as Record<string, unknown>).__ptyConnectDiag ??= [] as string[]) as string[]
-    ;((globalThis as Record<string, unknown>).__ptyConnectDiag as string[]).push(_diagMsg)
+    recordPtyConnectDiagnostic(
+      `pane=${pane.id} tab=${deps.tabId} restored=${restoredPtyId} existing=${existingPtyId} detached=${detachedLivePtyId} reattach=${deferredReattachSessionId} hasTransport=${hasExistingPaneTransport} pendingKey=${pendingSpawnKey}`
+    )
 
     if (deferredReattachSessionId) {
       allowInitialIdleCacheSeed = true
-      console.log(`[pty-connect] pane=${pane.id} → REATTACH ${deferredReattachSessionId}`)
-      ;((globalThis as Record<string, unknown>).__ptyConnectDiag as string[])?.push(
-        `pane=${pane.id} → REATTACH`
-      )
+      recordPtyConnectDiagnostic(`pane=${pane.id} -> REATTACH ${deferredReattachSessionId}`)
 
       // Why: reattach also pre-signals so the cooperation gate suppresses
       // the daemon seed for this paneKey. Reattach paths register their
@@ -1174,10 +1185,7 @@ export function connectPanePty(
           startFreshSpawn()
         })
     } else if (detachedLivePtyId) {
-      console.log(`[pty-connect] pane=${pane.id} → ATTACH detached=${detachedLivePtyId}`)
-      ;((globalThis as Record<string, unknown>).__ptyConnectDiag as string[])?.push(
-        `pane=${pane.id} → ATTACH ${detachedLivePtyId}`
-      )
+      recordPtyConnectDiagnostic(`pane=${pane.id} -> ATTACH detached=${detachedLivePtyId}`)
       allowInitialIdleCacheSeed = false
       // Why: surface synchronous attach failures (e.g., the PTY died between
       // mount and remount, so window.api.pty.resize rejects) through
@@ -1210,10 +1218,7 @@ export function connectPanePty(
       allowInitialIdleCacheSeed = false
       const pendingSpawn = pendingSpawnByPaneKey.get(pendingSpawnKey)
       if (pendingSpawn) {
-        console.log(`[pty-connect] pane=${pane.id} → PENDING SPAWN (waiting on same leaf)`)
-        ;((globalThis as Record<string, unknown>).__ptyConnectDiag as string[])?.push(
-          `pane=${pane.id} → PENDING SPAWN`
-        )
+        recordPtyConnectDiagnostic(`pane=${pane.id} -> PENDING SPAWN`)
         void pendingSpawn
           .then((spawnedPtyId) => {
             if (disposed) {
@@ -1254,10 +1259,7 @@ export function connectPanePty(
             reportError(err instanceof Error ? err.message : String(err))
           })
       } else {
-        console.log(`[pty-connect] pane=${pane.id} → FRESH SPAWN`)
-        ;((globalThis as Record<string, unknown>).__ptyConnectDiag as string[])?.push(
-          `pane=${pane.id} → FRESH SPAWN`
-        )
+        recordPtyConnectDiagnostic(`pane=${pane.id} -> FRESH SPAWN`)
         startFreshSpawn()
       }
     }

src/renderer/src/components/terminal-pane/remote-runtime-pty-transport.test.ts

@@ -91,6 +91,24 @@ describe('createRemoteRuntimePtyTransport', () => {
     )
   }
 
+  function emitSnapshotFrame(
+    streamId: number,
+    opcode:
+      | TerminalStreamOpcode.SnapshotStart
+      | TerminalStreamOpcode.SnapshotChunk
+      | TerminalStreamOpcode.SnapshotEnd,
+    payload: Uint8Array<ArrayBufferLike>
+  ): void {
+    subscriptionCallbacks?.onBinary?.(
+      encodeTerminalStreamFrame({
+        opcode,
+        streamId,
+        seq: 1,
+        payload
+      })
+    )
+  }
+
   beforeEach(() => {
     vi.resetModules()
     vi.clearAllMocks()
@@ -509,4 +527,37 @@ describe('createRemoteRuntimePtyTransport', () => {
     expect(onBell).not.toHaveBeenCalled()
     expect(onConnect).toHaveBeenCalled()
   })
+
+  it('bounds oversized binary snapshots without closing the live stream', async () => {
+    const { createRemoteRuntimePtyTransport } = await import('./remote-runtime-pty-transport')
+    const onReplayData = vi.fn()
+    const onData = vi.fn()
+    const onError = vi.fn()
+    const onConnect = vi.fn()
+    const transport = createRemoteRuntimePtyTransport('env-1', {
+      worktreeId: 'wt-1'
+    })
+
+    await transport.connect({ url: '', callbacks: { onReplayData, onData, onError, onConnect } })
+    await vi.waitFor(() => expect(subscriptionSendBinary).toHaveBeenCalled())
+    const { streamId } = latestSubscribePayload()
+
+    emitSnapshotFrame(
+      streamId,
+      TerminalStreamOpcode.SnapshotStart,
+      encodeTerminalStreamJson({ kind: 'scrollback' })
+    )
+    emitSnapshotFrame(streamId, TerminalStreamOpcode.SnapshotChunk, new Uint8Array(1024 * 1024))
+    emitSnapshotFrame(streamId, TerminalStreamOpcode.SnapshotChunk, new Uint8Array(1024 * 1024))
+    emitSnapshotFrame(streamId, TerminalStreamOpcode.SnapshotChunk, new Uint8Array(1))
+    emitSnapshotFrame(streamId, TerminalStreamOpcode.SnapshotEnd, new Uint8Array())
+    emitOutput(streamId, 'live-after-overflow')
+
+    expect(onReplayData).not.toHaveBeenCalled()
+    expect(onError).toHaveBeenCalledWith(
+      'Remote terminal snapshot exceeded the 2 MiB replay limit; live output will continue.'
+    )
+    expect(onConnect).toHaveBeenCalled()
+    expect(onData).toHaveBeenCalledWith('live-after-overflow')
+  })
 })

src/renderer/src/runtime/remote-runtime-terminal-multiplexer.ts

@@ -63,9 +63,14 @@ type RemoteRuntimeMultiplexedTerminalState = {
   terminal: string
   callbacks: RemoteRuntimeMultiplexedTerminalCallbacks
   snapshotChunks: Uint8Array<ArrayBufferLike>[]
+  snapshotBytes: number
+  snapshotOverflowed: boolean
 }
 
 const CONTROL_STREAM_ID = 0
+const MAX_REMOTE_TERMINAL_SNAPSHOT_BYTES = 2 * 1024 * 1024
+const REMOTE_TERMINAL_SNAPSHOT_TOO_LARGE =
+  'Remote terminal snapshot exceeded the 2 MiB replay limit; live output will continue.'
 
 class RemoteRuntimeTerminalMultiplexer {
   private readonly streams = new Map<number, RemoteRuntimeMultiplexedTerminalState>()
@@ -89,7 +94,9 @@ class RemoteRuntimeTerminalMultiplexer {
       streamId,
       terminal: args.terminal,
       callbacks: args.callbacks,
-      snapshotChunks: []
+      snapshotChunks: [],
+      snapshotBytes: 0,
+      snapshotOverflowed: false
     }
     this.streams.set(streamId, state)
 
@@ -216,10 +223,12 @@ class RemoteRuntimeTerminalMultiplexer {
       return
     }
     if (event.type === 'end') {
+      clearSnapshot(stream)
       this.streams.delete(event.streamId)
       stream.callbacks.onEnd?.()
       this.closeIfIdle()
     } else if (event.type === 'error') {
+      clearSnapshot(stream)
       stream.callbacks.onError?.(
         typeof event.message === 'string' ? event.message : 'Remote terminal stream failed.'
       )
@@ -258,20 +267,33 @@ class RemoteRuntimeTerminalMultiplexer {
       return
     }
     if (frame.opcode === TerminalStreamOpcode.SnapshotStart) {
-      stream.snapshotChunks = []
+      clearSnapshot(stream)
       return
     }
     if (frame.opcode === TerminalStreamOpcode.SnapshotChunk) {
+      if (stream.snapshotOverflowed) {
+        return
+      }
+      stream.snapshotBytes += frame.payload.byteLength
+      if (stream.snapshotBytes > MAX_REMOTE_TERMINAL_SNAPSHOT_BYTES) {
+        clearSnapshot(stream)
+        stream.snapshotOverflowed = true
+        stream.callbacks.onError?.(REMOTE_TERMINAL_SNAPSHOT_TOO_LARGE)
+        return
+      }
       stream.snapshotChunks.push(frame.payload)
       return
     }
     if (frame.opcode === TerminalStreamOpcode.SnapshotEnd) {
-      stream.callbacks.onSnapshot(decodeTerminalStreamText(concatBytes(stream.snapshotChunks)))
-      stream.snapshotChunks = []
+      if (!stream.snapshotOverflowed) {
+        stream.callbacks.onSnapshot(decodeTerminalStreamText(concatBytes(stream.snapshotChunks)))
+      }
+      clearSnapshot(stream)
       stream.callbacks.onSubscribed?.()
       return
     }
     if (frame.opcode === TerminalStreamOpcode.Error) {
+      clearSnapshot(stream)
       stream.callbacks.onError?.(decodeTerminalStreamText(frame.payload))
     }
   }
@@ -318,6 +340,7 @@ class RemoteRuntimeTerminalMultiplexer {
     this.subscription = null
     this.streams.clear()
     for (const stream of streams) {
+      clearSnapshot(stream)
       stream.callbacks.onTransportClose?.()
       if (message) {
         stream.callbacks.onError?.(message)
@@ -364,6 +387,12 @@ function concatBytes(chunks: Uint8Array<ArrayBufferLike>[]): Uint8Array<ArrayBuf
   return out
 }
 
+function clearSnapshot(stream: RemoteRuntimeMultiplexedTerminalState): void {
+  stream.snapshotChunks = []
+  stream.snapshotBytes = 0
+  stream.snapshotOverflowed = false
+}
+
 function isTerminalDriverState(
   value: unknown
 ): value is { kind: 'idle' } | { kind: 'desktop' } | { kind: 'mobile'; clientId: string } {

src/renderer/src/store/slices/editor.test.ts

@@ -866,6 +866,24 @@ describe('createEditorSlice remote branch actions', () => {
     })
   })
 
+  it('does not notify subscribers when upstream status is unchanged', () => {
+    const store = createEditorStore()
+    const status = {
+      hasUpstream: true,
+      upstreamName: 'origin/main',
+      ahead: 2,
+      behind: 1
+    }
+
+    store.getState().setUpstreamStatus('wt-1', status)
+    const listener = vi.fn()
+    const unsubscribe = store.subscribe(listener)
+    store.getState().setUpstreamStatus('wt-1', { ...status })
+    unsubscribe()
+
+    expect(listener).not.toHaveBeenCalled()
+  })
+
   it('runs pull and refreshes status + upstream on success', async () => {
     const store = createEditorStore()
     store.getState().setGitStatus('wt-1', {

src/renderer/src/store/slices/editor.ts

@@ -1960,12 +1960,17 @@ export const createEditorSlice: StateCreator<AppState, [], [], EditorSlice> = (s
     }),
   remoteStatusesByWorktree: {},
   setUpstreamStatus: (worktreeId, status) =>
-    set((s) => ({
-      remoteStatusesByWorktree: {
-        ...s.remoteStatusesByWorktree,
-        [worktreeId]: status
+    set((s) => {
+      if (areUpstreamStatusesEqual(s.remoteStatusesByWorktree[worktreeId], status)) {
+        return s
       }
-    })),
+      return {
+        remoteStatusesByWorktree: {
+          ...s.remoteStatusesByWorktree,
+          [worktreeId]: status
+        }
+      }
+    }),
   isRemoteOperationActive: false,
   remoteOperationDepth: 0,
   inFlightRemoteOpKind: null,
@@ -2525,6 +2530,19 @@ function areTrackedConflictMapsEqual(
   return prevKeys.length === nextKeys.length && prevKeys.every((key) => prev[key] === next[key])
 }
 
+function areUpstreamStatusesEqual(
+  prev: GitUpstreamStatus | undefined,
+  next: GitUpstreamStatus
+): boolean {
+  return (
+    prev !== undefined &&
+    prev.hasUpstream === next.hasUpstream &&
+    prev.upstreamName === next.upstreamName &&
+    prev.ahead === next.ahead &&
+    prev.behind === next.behind
+  )
+}
+
 function reconcileOpenFilesForStatus(
   openFiles: OpenFile[],
   worktreeId: string,

src/renderer/src/store/slices/store-cascades.test.ts

@@ -60,6 +60,7 @@ import {
   makeWorktree,
   seedStore
 } from './store-test-helpers'
+import { shutdownBufferCaptures } from '@/components/terminal-pane/shutdown-buffer-captures'
 
 // ─── Tests ────────────────────────────────────────────────────────────
 
@@ -1366,6 +1367,28 @@ describe('shutdownWorktreeTerminals (sleep) — agent status hygiene', () => {
   beforeEach(() => {
     vi.clearAllMocks()
     mockApi.pty.kill.mockResolvedValue(undefined)
+    shutdownBufferCaptures.clear()
+  })
+
+  it('asks sleep-time buffer capture to skip local scrollback serialization', async () => {
+    const store = createTestStore()
+    const wt = 'repo1::/path/wt1'
+    const capture = vi.fn()
+
+    seedStore(store, {
+      worktreesByRepo: {
+        repo1: [makeWorktree({ id: wt, repoId: 'repo1', path: '/path/wt1' })]
+      },
+      tabsByWorktree: {
+        [wt]: [makeTab({ id: 'tab-1', worktreeId: wt, ptyId: 'pty-1' })]
+      },
+      ptyIdsByTabId: { 'tab-1': ['pty-1'] }
+    })
+    shutdownBufferCaptures.set('tab-1', capture)
+
+    await store.getState().shutdownWorktreeTerminals(wt, { keepIdentifiers: true })
+
+    expect(capture).toHaveBeenCalledWith({ includeLocalBuffers: false })
   })
 
   it('drops live agentStatusByPaneKey entries on sleep so the working row disappears', async () => {

src/renderer/src/store/slices/terminals.ts

@@ -1111,15 +1111,15 @@ export const createTerminalSlice: StateCreator<AppState, [], [], TerminalSlice>
     // subsequent set must use a functional updater spreading
     // s.terminalLayoutsByTabId, not a captured snapshot). For SSH this is
     // load-bearing — the relay drops the remote PTY on kill so there's no
-    // on-disk history dir to cold-restore from. For local daemon it's
-    // defense-in-depth alongside the on-disk history dir preserved by
-    // keepHistory below.
+    // on-disk history dir to cold-restore from. Local daemon scrollback is
+    // intentionally skipped because the session payload prunes it and daemon
+    // history/checkpoints are authoritative.
     if (keepIdentifiers) {
       for (const tab of tabs) {
         const capture = shutdownBufferCaptures.get(tab.id)
         if (capture) {
           try {
-            capture()
+            capture({ includeLocalBuffers: false })
           } catch {
             // Don't let one tab's capture failure block the rest.
           }