feat(chat): desktop prompt navigator rail (#2054)

* feat(chat): add desktop prompt navigator rail

Add a ChatGPT-style right-center prompt marker rail for web/desktop chat
with hover/keyboard preview panel, load-more for partial history (panel only),
Chat setting, and mod+alt+p shortcut. Disabled in VS Code across rail,
shortcut, settings, help, and search surfaces.

Co-authored-by: Serhii Dziupin <makeittech@users.noreply.github.com>

* fix(ui): read promptNavigatorEnabled from getState in shortcut handler

Match the file convention used by other shortcut handlers so the toggle
does not rely on a hook-level selector closure.

Co-authored-by: Serhii Dziupin <makeittech@users.noreply.github.com>

* fix(ui): drop use-no-memo and default prompt navigator off

Remove the project-unprecedented React Compiler opt-out, and ship the
prompt navigator as opt-in to match other recent chat UI toggles.

Co-authored-by: Serhii Dziupin <makeittech@users.noreply.github.com>

---------

Co-authored-by: Cursor Agent <cursoragent@cursor.com>
Co-authored-by: Serhii Dziupin <makeittech@users.noreply.github.com>

packages/ui/src/hooks/useKeyboardShortcuts.ts

@@ -35,6 +35,8 @@ export const useKeyboardShortcuts = () => {
   const setSettingsDialogOpen = useUIStore((s) => s.setSettingsDialogOpen);
   const setModelSelectorOpen = useUIStore((s) => s.setModelSelectorOpen);
   const setTimelineDialogOpen = useUIStore((s) => s.setTimelineDialogOpen);
+  const togglePromptNavigatorPanel = useUIStore((s) => s.togglePromptNavigatorPanel);
+  const setPromptNavigatorPanelOpen = useUIStore((s) => s.setPromptNavigatorPanelOpen);
   const toggleExpandedInput = useUIStore((s) => s.toggleExpandedInput);
   const shortcutOverrides = useUIStore((s) => s.shortcutOverrides);
   const currentDirectory = useDirectoryStore((s) => s.currentDirectory);
@@ -142,6 +144,42 @@ export const useKeyboardShortcuts = () => {
         return;
       }
 
+      if (eventMatchesShortcut(e, combo('toggle_prompt_navigator'))) {
+        const {
+          activeMainTab,
+          promptNavigatorEnabled,
+          isSettingsDialogOpen,
+          isCommandPaletteOpen,
+          isHelpDialogOpen,
+          isSessionSwitcherOpen,
+          isAboutDialogOpen,
+          isTimelineDialogOpen,
+          isMultiRunLauncherOpen,
+          isImagePreviewOpen,
+        } = useUIStore.getState();
+
+        if (!promptNavigatorEnabled || isMobile || isVSCodeRuntime() || activeMainTab !== 'chat') {
+          return;
+        }
+
+        const hasOverlay = isSettingsDialogOpen
+          || isCommandPaletteOpen
+          || isHelpDialogOpen
+          || isSessionSwitcherOpen
+          || isAboutDialogOpen
+          || isTimelineDialogOpen
+          || isMultiRunLauncherOpen
+          || isImagePreviewOpen;
+
+        if (hasOverlay) {
+          return;
+        }
+
+        e.preventDefault();
+        togglePromptNavigatorPanel();
+        return;
+      }
+
       if (eventMatchesShortcut(e, combo('open_status'))) {
         e.preventDefault();
         void showOpenCodeStatus();
@@ -505,6 +543,7 @@ export const useKeyboardShortcuts = () => {
           isMultiRunLauncherOpen,
           isImagePreviewOpen,
           activeMainTab,
+          isPromptNavigatorPanelOpen,
         } = useUIStore.getState();
 
         if (isInsideDialog || isInsideTerminal || hasDropdownInteraction) {
@@ -512,6 +551,13 @@ export const useKeyboardShortcuts = () => {
           return;
         }
 
+        if (isPromptNavigatorPanelOpen) {
+          e.preventDefault();
+          setPromptNavigatorPanelOpen(false);
+          resetAbortPriming();
+          return;
+        }
+
         // If settings is open, close it
         if (isSettingsDialogOpen) {
           e.preventDefault();
@@ -594,6 +640,8 @@ export const useKeyboardShortcuts = () => {
     setSettingsDialogOpen,
     setModelSelectorOpen,
     setTimelineDialogOpen,
+    togglePromptNavigatorPanel,
+    setPromptNavigatorPanelOpen,
     toggleExpandedInput,
     setThemeMode,
     working,