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

CHECKPOINT_BS_NOT_FOR_COMMIT

Setting schema stuff missed earlier.

Tool Result display fixes.

Checkpoint no commit.

Checkpoint of compile fixes

feat: Auto-scroll to bottom via Events

feat: Auto-scroll to bottom on exiting mouse mode

Fix snapshots

docs/cli/settings.md

@@ -74,6 +74,8 @@ they appear in the UI.
 | Show Model Info In Chat              | `ui.showModelInfoInChat`               | Show the model name in the chat for each model turn.                                                                                                              | `false`  |
 | Show User Identity                   | `ui.showUserIdentity`                  | Show the signed-in user's identity (e.g. email) in the UI.                                                                                                        | `true`   |
 | Use Alternate Screen Buffer          | `ui.useAlternateBuffer`                | Use an alternate screen buffer for the UI, preserving shell history.                                                                                              | `false`  |
+| Render Process                       | `ui.renderProcess`                     | Enable Ink render process for the UI.                                                                                                                             | `true`   |
+| Terminal Buffer                      | `ui.terminalBuffer`                    | Use the new terminal buffer architecture for rendering.                                                                                                           | `true`   |
 | Use Background Color                 | `ui.useBackgroundColor`                | Whether to use background colors in the UI.                                                                                                                       | `true`   |
 | Incremental Rendering                | `ui.incrementalRendering`              | Enable incremental rendering for the UI. This option will reduce flickering but may cause rendering artifacts. Only supported when useAlternateBuffer is enabled. | `true`   |
 | Show Spinner                         | `ui.showSpinner`                       | Show the spinner during operations.                                                                                                                               | `true`   |