perf(ui): lazy-load markdown and defer diff rendering (#215)

## Summary
- lazy-load the markdown and diff render paths so they stop inflating
initial UI startup work
- move shared text rendering helpers out of the markdown path and keep
diff rendering on the deferred path
- defer the Monaco secondary viewers so the markdown and diff path no
longer keeps that work in the main bundle

## Follow-ups
- related fork follow-up: Pagecran/CodeNomad#1
- that follow-up is now independent on dev and only keeps the remaining
right panel, picker, and tool-call secondary chunking work

## Testing
- npm run typecheck --workspace @codenomad/ui
- npm run build --workspace @codenomad/ui

packages/ui/src/lib/i18n/messages/en/instance.ts

@@ -114,6 +114,10 @@ export const instanceMessages = {
   "instanceShell.sessionChanges.filesChanged": "{count} files changed",
   "instanceShell.sessionChanges.actions.show": "Show changes",
 
+  "instanceShell.gitChanges.loading": "Loading git changes...",
+  "instanceShell.gitChanges.empty": "No git changes yet.",
+  "instanceShell.gitChanges.deleted": "Deleted",
+
   "instanceShell.filesShell.fileListTitle": "File list",
   "instanceShell.filesShell.mobileSelectorLabel": "Select file",
   "instanceShell.filesShell.mobileSelectorEmpty": "Select a file",

packages/ui/src/lib/i18n/messages/es/instance.ts

@@ -90,6 +90,7 @@ export const instanceMessages = {
 
   "instanceShell.rightPanel.title": "Panel de estado",
   "instanceShell.rightPanel.tabs.changes": "Cambios",
+  "instanceShell.rightPanel.tabs.gitChanges": "Cambios de Git",
   "instanceShell.rightPanel.tabs.files": "Archivos",
   "instanceShell.rightPanel.tabs.status": "Estado",
   "instanceShell.rightPanel.tabs.ariaLabel": "Pestañas del panel derecho",
@@ -112,6 +113,10 @@ export const instanceMessages = {
   "instanceShell.sessionChanges.filesChanged": "{count} archivos cambiados",
   "instanceShell.sessionChanges.actions.show": "Mostrar cambios",
 
+  "instanceShell.gitChanges.loading": "Cargando cambios de Git...",
+  "instanceShell.gitChanges.empty": "Aún no hay cambios de Git.",
+  "instanceShell.gitChanges.deleted": "Eliminado",
+
   "instanceShell.filesShell.fileListTitle": "Lista de archivos",
   "instanceShell.filesShell.mobileSelectorLabel": "Seleccionar archivo",
   "instanceShell.filesShell.mobileSelectorEmpty": "Selecciona un archivo",

packages/ui/src/lib/i18n/messages/fr/instance.ts

@@ -90,6 +90,7 @@ export const instanceMessages = {
 
   "instanceShell.rightPanel.title": "Panneau d'état",
   "instanceShell.rightPanel.tabs.changes": "Modifications",
+  "instanceShell.rightPanel.tabs.gitChanges": "Changements Git",
   "instanceShell.rightPanel.tabs.files": "Fichiers",
   "instanceShell.rightPanel.tabs.status": "Statut",
   "instanceShell.rightPanel.tabs.ariaLabel": "Onglets du panneau droit",
@@ -112,6 +113,10 @@ export const instanceMessages = {
   "instanceShell.sessionChanges.filesChanged": "{count} fichiers modifiés",
   "instanceShell.sessionChanges.actions.show": "Afficher les changements",
 
+  "instanceShell.gitChanges.loading": "Chargement des changements Git...",
+  "instanceShell.gitChanges.empty": "Aucun changement Git pour l'instant.",
+  "instanceShell.gitChanges.deleted": "Supprimé",
+
   "instanceShell.filesShell.fileListTitle": "Liste des fichiers",
   "instanceShell.filesShell.mobileSelectorLabel": "Sélectionner un fichier",
   "instanceShell.filesShell.mobileSelectorEmpty": "Sélectionnez un fichier",

packages/ui/src/lib/i18n/messages/ja/instance.ts

@@ -90,6 +90,7 @@ export const instanceMessages = {
 
   "instanceShell.rightPanel.title": "ステータスパネル",
   "instanceShell.rightPanel.tabs.changes": "変更",
+  "instanceShell.rightPanel.tabs.gitChanges": "Git 変更",
   "instanceShell.rightPanel.tabs.files": "ファイル",
   "instanceShell.rightPanel.tabs.status": "ステータス",
   "instanceShell.rightPanel.tabs.ariaLabel": "右パネルのタブ",
@@ -112,6 +113,10 @@ export const instanceMessages = {
   "instanceShell.sessionChanges.filesChanged": "{count} 個のファイルが変更されました",
   "instanceShell.sessionChanges.actions.show": "変更を表示",
 
+  "instanceShell.gitChanges.loading": "Git の変更を読み込み中...",
+  "instanceShell.gitChanges.empty": "Git の変更はまだありません。",
+  "instanceShell.gitChanges.deleted": "削除済み",
+
   "instanceShell.filesShell.fileListTitle": "ファイル一覧",
   "instanceShell.filesShell.mobileSelectorLabel": "ファイルを選択",
   "instanceShell.filesShell.mobileSelectorEmpty": "ファイルを選択してください",

packages/ui/src/lib/i18n/messages/ru/instance.ts

@@ -90,6 +90,7 @@ export const instanceMessages = {
 
   "instanceShell.rightPanel.title": "Панель состояния",
   "instanceShell.rightPanel.tabs.changes": "Изменения",
+  "instanceShell.rightPanel.tabs.gitChanges": "Изменения Git",
   "instanceShell.rightPanel.tabs.files": "Файлы",
   "instanceShell.rightPanel.tabs.status": "Статус",
   "instanceShell.rightPanel.tabs.ariaLabel": "Вкладки правой панели",
@@ -112,6 +113,10 @@ export const instanceMessages = {
   "instanceShell.sessionChanges.filesChanged": "Изменено файлов: {count}",
   "instanceShell.sessionChanges.actions.show": "Показать изменения",
 
+  "instanceShell.gitChanges.loading": "Загрузка изменений Git...",
+  "instanceShell.gitChanges.empty": "Изменений Git пока нет.",
+  "instanceShell.gitChanges.deleted": "Удалено",
+
   "instanceShell.filesShell.fileListTitle": "Список файлов",
   "instanceShell.filesShell.mobileSelectorLabel": "Выбрать файл",
   "instanceShell.filesShell.mobileSelectorEmpty": "Выберите файл",

packages/ui/src/lib/i18n/messages/zh-Hans/instance.ts

@@ -90,6 +90,7 @@ export const instanceMessages = {
 
   "instanceShell.rightPanel.title": "状态面板",
   "instanceShell.rightPanel.tabs.changes": "更改",
+  "instanceShell.rightPanel.tabs.gitChanges": "Git 更改",
   "instanceShell.rightPanel.tabs.files": "文件",
   "instanceShell.rightPanel.tabs.status": "状态",
   "instanceShell.rightPanel.tabs.ariaLabel": "右侧面板标签页",
@@ -112,6 +113,10 @@ export const instanceMessages = {
   "instanceShell.sessionChanges.filesChanged": "已更改 {count} 个文件",
   "instanceShell.sessionChanges.actions.show": "显示更改",
 
+  "instanceShell.gitChanges.loading": "正在加载 Git 更改...",
+  "instanceShell.gitChanges.empty": "暂无 Git 更改。",
+  "instanceShell.gitChanges.deleted": "已删除",
+
   "instanceShell.filesShell.fileListTitle": "文件列表",
   "instanceShell.filesShell.mobileSelectorLabel": "选择文件",
   "instanceShell.filesShell.mobileSelectorEmpty": "请选择文件",