fix(desktop): close the peek's three timer races

Review round 1 (Cursor Bugbot) found three ways the card could flicker:

- A modal opening mid-dwell left the open timer pending, so the card
  mounted over the modal before the dismiss path could run.
- A modal opening while the card was already animating out let it keep
  animating on top of the modal.
- Re-hovering the toggle late in the exit window scheduled a fresh dwell
  without clearing the exit timer, so the card unmounted and then
  re-mounted — a visible gap with the pointer never leaving the toggle.

The first two collapse into one fix: merge the two reset effects so an
unavailable peek and a screen-owning modal both drop the card immediately,
unconditionally clearing all three timers. Instant is also the right look,
since the modal's scrim covers the card's position on the same frame.

For the third, a re-hover during the exit now re-opens synchronously rather
than scheduling another dwell — the card is already on screen, so the dwell
that guards against accidental opens from a cold state does not apply.

One regression test each.

Author: Waleed Latif

apps/sim/app/workspace/[workspaceId]/components/workspace-chrome/use-sidebar-peek.test.tsx

@@ -300,6 +300,59 @@ describe('useSidebarPeek', () => {
     expect(active.state().isPeekActive).toBe(false)
   })
 
+  it('never mounts the card when a modal opens mid-dwell', () => {
+    active = renderPeek(true)
+
+    act(() => {
+      active?.triggerEnter()
+      vi.advanceTimersByTime(OPEN_DELAY_MS - 20)
+    })
+    active.setDismissed(true)
+    act(() => {
+      vi.advanceTimersByTime(OPEN_DELAY_MS * 2)
+    })
+
+    expect(active.state().isPeekActive).toBe(false)
+  })
+
+  it('drops an already-exiting card the instant a modal opens', () => {
+    active = renderPeek(true)
+    openPeek(active)
+    movePointerTo(POINT.onContent)
+    act(() => {
+      vi.advanceTimersByTime(CLOSE_DELAY_MS)
+    })
+    expect(active.state().isPeekActive).toBe(true)
+
+    active.setDismissed(true)
+
+    expect(active.state().isPeekActive).toBe(false)
+  })
+
+  it('snaps a card that is animating out back open on re-hover', () => {
+    active = renderPeek(true)
+    openPeek(active)
+    movePointerTo(POINT.onContent)
+    act(() => {
+      vi.advanceTimersByTime(CLOSE_DELAY_MS)
+    })
+    // Mid-exit: mounted but no longer open.
+    expect(active.state().isPeekActive).toBe(true)
+    expect(active.state().isPeekOpen).toBe(false)
+
+    // Re-hover late in the exit window; the pending exit timer must not win.
+    act(() => {
+      vi.advanceTimersByTime(EXIT_DURATION_MS - 20)
+      active?.triggerEnter()
+    })
+    expect(active.state().isPeekOpen).toBe(true)
+
+    act(() => {
+      vi.advanceTimersByTime(EXIT_DURATION_MS * 2)
+    })
+    expect(active.state().isPeekOpen).toBe(true)
+  })
+
   it('retracts when a modal opens, even with the pointer inside', () => {
     active = renderPeek(true)
     openPeek(active)

apps/sim/app/workspace/[workspaceId]/components/workspace-chrome/use-sidebar-peek.ts

@@ -145,29 +145,39 @@ export function useSidebarPeek(enabled: boolean, dismissed = false): SidebarPeek
     if (!enabled || dismissed) return
     clearTimer(closeTimerRef)
     clearTimer(openTimerRef)
+    // Still on screen and animating out: snap it back instead of waiting out another
+    // dwell, which the pending exit timer would win — unmounting the card and then
+    // re-mounting it, a visible flicker with the pointer never leaving the toggle.
+    if (phase === 'exiting') {
+      open()
+      return
+    }
     openTimerRef.current = setTimeout(() => {
       openTimerRef.current = null
       open()
     }, PEEK_OPEN_DELAY_MS)
-  }, [dismissed, enabled, open])
+  }, [dismissed, enabled, open, phase])
 
   const onTriggerLeave = useCallback(() => {
     clearTimer(openTimerRef)
   }, [])
 
-  /** Drop the card outright — no exit animation — once the peek stops being available. */
+  /**
+   * Drop the card outright — no exit animation — the moment the peek stops being
+   * available (⌘B, fullscreen) or a modal takes the screen.
+   *
+   * Unconditional rather than gated on the current phase, because every phase needs
+   * clearing: a pending dwell would otherwise fire and mount the card over the modal,
+   * and an in-flight exit would keep animating on top of it. Instant is also right
+   * visually — the modal's own scrim covers the card's position on the same frame.
+   */
   useEffect(() => {
-    if (enabled) return
+    if (enabled && !dismissed) return
     clearTimer(openTimerRef)
     clearTimer(closeTimerRef)
     clearTimer(exitTimerRef)
     setPhase('closed')
-  }, [enabled])
-
-  /** A modal is a destination and owns the screen, so the transient card yields to it. */
-  useEffect(() => {
-    if (dismissed && phase === 'open') close()
-  }, [close, dismissed, phase])
+  }, [dismissed, enabled])
 
   useEffect(() => {
     if (phase !== 'open') return