fix(gui): address review — stale smoke case, tooltip trigger overlap, collapse contract docs

- The real-browser collapse smoke tracked the old chrome: visible HARNESS
  text (the wordmark svg is aria-hidden now), an 'Expand sidebar' label
  (renamed 'Open sidebar'), a 300px settle (default is 280), and an
  immediate focus assert (rail search defers focus past the slide). The
  case now tracks the brand span, polls the deferred focus, and uses the
  current labels and width.
- Tooltip treated hover and focus as one trigger: leaving with the mouse
  dropped the bubble of a still-focused anchor (and vice versa). The two
  triggers are tracked independently; the bubble hides only after both
  clear. Spec pins both orders.
- The ui-sidebar README and the bilingual collapse note still described
  the retired geometry morph; both now state the slide + crossfade
  contract, the fixed-width (never-conceding) sidebar, and the rail's
  whale-mark/tooltip chrome.

packages/client/ui-primitives/tests/tooltip.spec.tsx

@@ -81,6 +81,29 @@ describe('Tooltip', () => {
     expect(screen.getByRole('tooltip')).toBeTruthy()
   })
 
+  it('keeps the bubble while either hover or focus is still active', () => {
+    render(
+      <Tooltip label="Sticky">
+        <button type="button">anchor</button>
+      </Tooltip>,
+    )
+    const anchor = screen.getByText('anchor')
+    // Focused AND hovered: leaving with the mouse must not drop the bubble.
+    fireEvent.focus(anchor)
+    fireEvent.mouseEnter(anchor)
+    fireEvent.mouseLeave(anchor)
+    expect(screen.getByRole('tooltip')).toBeTruthy()
+    fireEvent.blur(anchor)
+    expect(screen.queryByRole('tooltip')).toBeNull()
+    // Symmetric: blurring while still hovered keeps it, mouseleave ends it.
+    fireEvent.mouseEnter(anchor)
+    fireEvent.focus(anchor)
+    fireEvent.blur(anchor)
+    expect(screen.getByRole('tooltip')).toBeTruthy()
+    fireEvent.mouseLeave(anchor)
+    expect(screen.queryByRole('tooltip')).toBeNull()
+  })
+
   it('drops an already-visible bubble when disabled flips mid-hover', () => {
     const { rerender } = render(
       <Tooltip label="Rail">