perf(checks-panel): gate the terminal-cwd poll on window visibility

The Checks panel polls window.api.pty.getCwd every 4s to follow the active
terminal's cwd. It was gated only on panel visibility (isPanelVisible), not
window visibility — so a hidden or minimized window kept spawning lsof on macOS
every 4s (the 4s cadence exceeds getCwd's 1.5s per-pid cache TTL, so every tick
is a guaranteed miss and a fresh subprocess).

Swap the raw window.setInterval for installWindowVisibilityInterval — the shared
helper every sibling timer already uses — which pauses while the window is hidden
and runs an immediate refresh on becoming visible so a cd made while hidden is
picked up on return. A visible-but-unfocused window (second monitor) keeps
polling, matching prior behavior.

Co-authored-by: Orca <help@stably.ai>

src/renderer/src/components/right-sidebar/use-checks-panel-terminal-worktree.test.ts

@@ -129,6 +129,36 @@ describe('useChecksPanelTerminalWorktree', () => {
     expect(latest?.worktree).toBe(parentWorktree)
   })
 
+  it('does not spawn getCwd while the window is hidden, then refreshes on becoming visible', async () => {
+    getCwdMock.mockResolvedValue(`${CHILD_PATH}/src`)
+    const setVisibility = (state: 'visible' | 'hidden'): void => {
+      Object.defineProperty(document, 'visibilityState', {
+        configurable: true,
+        get: () => state
+      })
+    }
+    setVisibility('hidden')
+    try {
+      await renderHook(parentWorktree)
+      await flushMicrotasks()
+      // Hidden window: no lsof-backed cwd probe at all.
+      expect(getCwdMock).not.toHaveBeenCalled()
+      expect(latest?.worktree).toBe(parentWorktree)
+
+      setVisibility('visible')
+      await act(async () => {
+        document.dispatchEvent(new Event('visibilitychange'))
+      })
+      await flushMicrotasks()
+      // Becoming visible runs an immediate refresh (a `cd` made while hidden
+      // is picked up promptly on return).
+      expect(getCwdMock).toHaveBeenCalledWith('pty-1')
+      expect(latest?.worktree).toBe(childWorktree)
+    } finally {
+      setVisibility('visible')
+    }
+  })
+
   it('keeps the default worktree when the cwd is outside every worktree', async () => {
     getCwdMock.mockResolvedValue('/tmp/scratch')
 

src/renderer/src/components/right-sidebar/use-checks-panel-terminal-worktree.ts

@@ -1,6 +1,7 @@
 import { useEffect, useMemo, useState } from 'react'
 import { useShallow } from 'zustand/react/shallow'
 import { useAppStore } from '@/store'
+import { installWindowVisibilityInterval } from '@/lib/window-visibility-interval'
 import { useAllWorktrees, useRepoMap } from '@/store/selectors'
 import { isRemoteRuntimePtyId } from '@/runtime/runtime-terminal-inspection'
 import { parseAppSshPtyId } from '../../../../shared/ssh-pty-id'
@@ -31,7 +32,8 @@ type ChecksPanelTerminalWorktree = {
  * the *remote* shell's OSC 7 path, which must not resolve a local worktree.
  * getCwd reads the local shell pid, so it is correct for that case. Remote
  * runtime PTYs are skipped (their cwd lives on the relay host). Polling is
- * gated on panel visibility, so a hidden panel does no background work and the
+ * gated on both panel visibility and window visibility, so a hidden panel or a
+ * hidden/minimized window does no background work (no `lsof` spawns) and the
  * caller's fallback worktree is used.
  *
  * Resolution is scoped to locally-executing worktrees: the cwd comes from a
@@ -123,11 +125,18 @@ export function useChecksPanelTerminalWorktree(args: {
       }
     }
 
-    void refresh()
-    const interval = window.setInterval(refresh, TERMINAL_CWD_POLL_MS)
+    // Why: getCwd shells out to `lsof` on macOS every tick (poll cadence >
+    // the 1.5s per-pid cache TTL, so each tick is a guaranteed miss). Gate on
+    // window visibility so a hidden/minimized window spawns no subprocesses;
+    // the helper runs an immediate refresh on becoming visible so a `cd` made
+    // while hidden is picked up promptly on return.
+    const stopInterval = installWindowVisibilityInterval({
+      run: () => void refresh(),
+      intervalMs: TERMINAL_CWD_POLL_MS
+    })
     return () => {
       disposed = true
-      window.clearInterval(interval)
+      stopInterval()
     }
   }, [activeTerminalPtyId, shouldPollCwd])