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/lib/i18n/messages/zh-TW.settings.ts

@@ -938,6 +938,7 @@
   'settings.openchamber.keyboardShortcuts.action.open_model_selector.label': '開啟模型選擇器',
   'settings.openchamber.keyboardShortcuts.action.expand_input.label': '展開輸入方塊',
   'settings.openchamber.keyboardShortcuts.action.open_timeline_dialog.label': '開啟對話時間軸',
+  'settings.openchamber.keyboardShortcuts.action.toggle_prompt_navigator.label': '顯示或隱藏提示詞導覽',
   'settings.projects.sidebar.total': '總計 {count}',
   'settings.projects.sidebar.actions.addProject': '新增專案',
   'settings.projects.page.empty.noProjects': '暫無專案。',
@@ -1681,6 +1682,8 @@
   'settings.openchamber.visual.field.collapsibleUserMessages': '收合較長的使用者訊息',
   'settings.openchamber.visual.field.stickyUserHeaderAria': '固定使用者訊息標頭',
   'settings.openchamber.visual.field.stickyUserHeader': '固定使用者訊息標頭',
+  'settings.openchamber.visual.field.promptNavigatorEnabledAria': '提示詞導覽',
+  'settings.openchamber.visual.field.promptNavigatorEnabled': '提示詞導覽',
   'settings.openchamber.visual.field.expandedEditorToolbarAria': 'Always show editor toolbar',
   'settings.openchamber.visual.field.expandedEditorToolbar': 'Always show editor toolbar (docked under the file tabs)',
   'settings.openchamber.visual.field.wideChatLayoutAria': '寬聊天佈局',