perf(dashboard): ignore unrelated store churn

src/renderer/src/components/dashboard/useAgentBucketCounts.ts

@@ -1,5 +1,6 @@
 import { useMemo } from 'react'
 import { useAppStore } from '@/store'
+import { useShallow } from 'zustand/react/shallow'
 import type { DashboardBucket } from '../../../../shared/dashboard-snapshot'
 import { buildDashboardSnapshot } from './build-dashboard-snapshot'
 
@@ -13,19 +14,33 @@ const EMPTY_COUNTS: AgentBucketCounts = { attention: 0, working: 0, idle: 0 }
  * only when an input slice changes (mirrors useDashboardData's cost profile).
  */
 export function useAgentBucketCounts(): AgentBucketCounts {
-  const repos = useAppStore((s) => s.repos)
-  const worktreesByRepo = useAppStore((s) => s.worktreesByRepo)
-  const tabsByWorktree = useAppStore((s) => s.tabsByWorktree)
-  const agentStatusByPaneKey = useAppStore((s) => s.agentStatusByPaneKey)
-  const retainedAgentsByPaneKey = useAppStore((s) => s.retainedAgentsByPaneKey)
-  const migrationUnsupportedByPtyId = useAppStore((s) => s.migrationUnsupportedByPtyId)
-  const runtimeAgentOrchestrationByPaneKey = useAppStore(
-    (s) => s.runtimeAgentOrchestrationByPaneKey
+  const {
+    repos,
+    worktreesByRepo,
+    tabsByWorktree,
+    agentStatusByPaneKey,
+    retainedAgentsByPaneKey,
+    migrationUnsupportedByPtyId,
+    runtimeAgentOrchestrationByPaneKey,
+    terminalLayoutsByTabId,
+    ptyIdsByTabId,
+    runtimePaneTitlesByTabId,
+    agentStatusEpoch
+  } = useAppStore(
+    useShallow((s) => ({
+      repos: s.repos,
+      worktreesByRepo: s.worktreesByRepo,
+      tabsByWorktree: s.tabsByWorktree,
+      agentStatusByPaneKey: s.agentStatusByPaneKey,
+      retainedAgentsByPaneKey: s.retainedAgentsByPaneKey,
+      migrationUnsupportedByPtyId: s.migrationUnsupportedByPtyId,
+      runtimeAgentOrchestrationByPaneKey: s.runtimeAgentOrchestrationByPaneKey,
+      terminalLayoutsByTabId: s.terminalLayoutsByTabId,
+      ptyIdsByTabId: s.ptyIdsByTabId,
+      runtimePaneTitlesByTabId: s.runtimePaneTitlesByTabId,
+      agentStatusEpoch: s.agentStatusEpoch
+    }))
   )
-  const terminalLayoutsByTabId = useAppStore((s) => s.terminalLayoutsByTabId)
-  const ptyIdsByTabId = useAppStore((s) => s.ptyIdsByTabId)
-  const runtimePaneTitlesByTabId = useAppStore((s) => s.runtimePaneTitlesByTabId)
-  const agentStatusEpoch = useAppStore((s) => s.agentStatusEpoch)
 
   return useMemo(() => {
     const snapshot = buildDashboardSnapshot(

src/renderer/src/components/dashboard/useDashboardPopoutBridge.test.tsx

@@ -34,7 +34,31 @@ vi.mock('@/lib/activate-tab-and-focus-pane', () => ({
   activateTabAndFocusPane: vi.fn()
 }))
 
-import { useDashboardPopoutBridge } from './useDashboardPopoutBridge'
+import {
+  dashboardSnapshotInputsChanged,
+  useDashboardPopoutBridge
+} from './useDashboardPopoutBridge'
+import type { DashboardSnapshotState } from './build-dashboard-snapshot'
+import type { AppState } from '@/store/types'
+
+type DashboardSnapshotWatchState = DashboardSnapshotState & Pick<AppState, 'agentStatusEpoch'>
+
+function makeSnapshotWatchState(): DashboardSnapshotWatchState {
+  return {
+    repos: [],
+    worktreesByRepo: {},
+    tabsByWorktree: {},
+    agentStatusByPaneKey: {},
+    retainedAgentsByPaneKey: {},
+    migrationUnsupportedByPtyId: {},
+    runtimeAgentOrchestrationByPaneKey: {},
+    terminalLayoutsByTabId: {},
+    ptyIdsByTabId: {},
+    runtimePaneTitlesByTabId: {},
+    acknowledgedAgentsByPaneKey: {},
+    agentStatusEpoch: 0
+  }
+}
 
 function Harness({ enabled }: { enabled: boolean }): null {
   useDashboardPopoutBridge(enabled)
@@ -80,6 +104,34 @@ describe('useDashboardPopoutBridge', () => {
     expect(mocks.subscribeStore).not.toHaveBeenCalled()
   })
 
+  it('ignores unrelated store writes while retaining every snapshot input', () => {
+    const previousState = makeSnapshotWatchState()
+    expect(dashboardSnapshotInputsChanged({ ...previousState }, previousState)).toBe(false)
+
+    const referenceInputs = [
+      'repos',
+      'worktreesByRepo',
+      'tabsByWorktree',
+      'agentStatusByPaneKey',
+      'retainedAgentsByPaneKey',
+      'migrationUnsupportedByPtyId',
+      'runtimeAgentOrchestrationByPaneKey',
+      'terminalLayoutsByTabId',
+      'ptyIdsByTabId',
+      'runtimePaneTitlesByTabId',
+      'acknowledgedAgentsByPaneKey'
+    ] as const
+    for (const key of referenceInputs) {
+      expect(
+        dashboardSnapshotInputsChanged({ ...previousState, [key]: {} }, previousState),
+        key
+      ).toBe(true)
+    }
+    expect(
+      dashboardSnapshotInputsChanged({ ...previousState, agentStatusEpoch: 1 }, previousState)
+    ).toBe(true)
+  })
+
   it('releases every dashboard listener when the experiment is disabled', async () => {
     await act(async () => root.render(<Harness enabled />))
 

src/renderer/src/components/dashboard/useDashboardPopoutBridge.ts

@@ -1,13 +1,36 @@
 import { useEffect } from 'react'
-import { useAppStore } from '@/store'
+import { useAppStore, type AppState } from '@/store'
 import { activateTabAndFocusPane } from '@/lib/activate-tab-and-focus-pane'
-import { buildDashboardSnapshot } from './build-dashboard-snapshot'
+import { buildDashboardSnapshot, type DashboardSnapshotState } from './build-dashboard-snapshot'
 
 // Why: cap snapshot rebuilds during bursts of agent-status pings. The board is a
 // glanceable surface, so ~4 updates/sec is plenty and keeps the cross-worktree
 // rebuild off the hot path.
 const PUBLISH_THROTTLE_MS = 250
 
+type DashboardSnapshotWatchState = DashboardSnapshotState & Pick<AppState, 'agentStatusEpoch'>
+
+export function dashboardSnapshotInputsChanged(
+  state: DashboardSnapshotWatchState,
+  previousState: DashboardSnapshotWatchState
+): boolean {
+  return (
+    state.repos !== previousState.repos ||
+    state.worktreesByRepo !== previousState.worktreesByRepo ||
+    state.tabsByWorktree !== previousState.tabsByWorktree ||
+    state.agentStatusByPaneKey !== previousState.agentStatusByPaneKey ||
+    state.retainedAgentsByPaneKey !== previousState.retainedAgentsByPaneKey ||
+    state.migrationUnsupportedByPtyId !== previousState.migrationUnsupportedByPtyId ||
+    state.runtimeAgentOrchestrationByPaneKey !== previousState.runtimeAgentOrchestrationByPaneKey ||
+    state.terminalLayoutsByTabId !== previousState.terminalLayoutsByTabId ||
+    state.ptyIdsByTabId !== previousState.ptyIdsByTabId ||
+    state.runtimePaneTitlesByTabId !== previousState.runtimePaneTitlesByTabId ||
+    state.acknowledgedAgentsByPaneKey !== previousState.acknowledgedAgentsByPaneKey ||
+    // Why: freshness can change a bucket without replacing any backing map.
+    state.agentStatusEpoch !== previousState.agentStatusEpoch
+  )
+}
+
 /**
  * Runs in the MAIN window (mount once in App). Two responsibilities:
  *  1. While the pop-out dashboard is open, derive the snapshot from the live
@@ -88,7 +111,12 @@ export function useDashboardPopoutBridge(enabled: boolean): void {
       open = next
       if (open) {
         if (!unsubscribeStore) {
-          unsubscribeStore = useAppStore.subscribe(publishThrottled)
+          unsubscribeStore = useAppStore.subscribe((state, previousState) => {
+            // Why: unrelated high-frequency store writes must not rebuild a cross-worktree snapshot.
+            if (dashboardSnapshotInputsChanged(state, previousState)) {
+              publishThrottled()
+            }
+          })
         }
         publishNow()
       } else {