feat: add config and keybindings for new ink terminal buffer mode

test: update test utils and resolve snapshot differences for ink changes

feat: refactor VirtualizedList to support static rendering and terminal buffers

feat: wire up AppContainer mouse mode and recording state for ink buffer

Fix stale ref in ScrollProvider breaking scrolling.

The ScrollProvider was getting stuck with a stale reference because the
`scrollables` Map was being registered and unregistered whenever the entry
identity changed. The underlying `ScrollableList` component dynamically created
a new ID which caused React remount cycles, while the `ScrollProvider` itself
suffered from state lag where the event handler ref was one tick behind the
actual registration.

This commit resolves these issues by:
1. Adding a stable `id` and `key` to `ScrollableList` in `MainContent.tsx`
2. Making `scrollablesRef` synchronously update in `ScrollProvider.tsx`
3. Using a proxy entry in `useScrollable` to avoid constant re-registering.

chore: add useEffect cleanup for ResizeObservers

Checkpoint fixing terminal buffer support.

Termina Serializer Optimization

packages/cli/src/ui/components/Help.test.tsx

@@ -72,7 +72,7 @@ describe('Help Component', () => {
 
     expect(output).toContain('Keyboard Shortcuts:');
     expect(output).toContain('Ctrl+C');
-    expect(output).toContain('Ctrl+S');
+    expect(output).toContain('Shift+Tab');
     expect(output).toContain('Page Up/Page Down');
     unmount();
   });