Add keyboard shortcut to create a new workspace

Cmd+N (Ctrl+N off mac) navigates to the new-workspace route through a
global handler keyed on the active host. The sidebar header row surfaces
the shortcut hint on hover, replacing the redundant "+" button that
duplicated the action in the Workspaces section header.

packages/app/src/i18n/resources.test.ts

@@ -299,6 +299,7 @@ describe("translation resources", () => {
     expect(en.settings.shortcuts.dialogTitle).toBe("Shortcuts");
     expect(en.settings.shortcuts.sections.tabsPanes).toBe("Tabs & Panes");
     expect(en.settings.shortcuts.help.toggleCommandCenter).toBe("Toggle command center");
+    expect(en.settings.shortcuts.help.newWorkspace).toBe("New workspace");
     expect(en.settings.shortcuts.helpNotes.showKeyboardShortcuts).toBe(
       "Available when focus is not in a text field or terminal.",
     );

packages/app/src/i18n/resources/ar.ts

@@ -1528,6 +1528,7 @@ export const ar: TranslationResources = {
       },
       help: {
         openProject: "مشروع مفتوح",
+        newWorkspace: "مساحة عمل جديدة",
         newWorktree: "شجرة عمل جديدة",
         archiveWorktree: "أرشفة شجرة العمل",
         newTab: "علامة تبويب جديدة",

packages/app/src/i18n/resources/en.ts

@@ -1533,6 +1533,7 @@ export const en = {
       },
       help: {
         openProject: "Open project",
+        newWorkspace: "New workspace",
         newWorktree: "New worktree",
         archiveWorktree: "Archive worktree",
         newTab: "New tab",

packages/app/src/i18n/resources/es.ts

@@ -1565,6 +1565,7 @@ export const es: TranslationResources = {
       },
       help: {
         openProject: "Abrir proyecto",
+        newWorkspace: "Nuevo espacio de trabajo",
         newWorktree: "Nuevo árbol de trabajo",
         archiveWorktree: "Árbol de trabajo de archivo",
         newTab: "Nueva pestaña",

packages/app/src/i18n/resources/fr.ts

@@ -1569,6 +1569,7 @@ export const fr: TranslationResources = {
       },
       help: {
         openProject: "Projet ouvert",
+        newWorkspace: "Nouvel espace de travail",
         newWorktree: "Nouvel arbre de travail",
         archiveWorktree: "Arbre de travail d'archivage",
         newTab: "Nouvel onglet",

packages/app/src/i18n/resources/ru.ts

@@ -1557,6 +1557,7 @@ export const ru: TranslationResources = {
       },
       help: {
         openProject: "Открыть проект",
+        newWorkspace: "Новое рабочее пространство",
         newWorktree: "Новое рабочее дерево",
         archiveWorktree: "Архив рабочего дерева",
         newTab: "Новая вкладка",

packages/app/src/i18n/resources/zh-CN.ts

@@ -1509,6 +1509,7 @@ export const zhCN: TranslationResources = {
       },
       help: {
         openProject: "打开项目",
+        newWorkspace: "新建 workspace",
         newWorktree: "新建 worktree",
         archiveWorktree: "归档 worktree",
         newTab: "新建标签",