feat(i18n): seed en.json and wire locale copy to app output

src/ClaudeDo.Localization/locales/en.json

@@ -0,0 +1,13 @@
+{
+  "metadata": { "code": "en", "name": "English" },
+  "settings": {
+    "title": "SETTINGS",
+    "save": "Save",
+    "cancel": "Cancel",
+    "language": "Language",
+    "tabGeneral": "General",
+    "tabWorktrees": "Worktrees",
+    "tabFiles": "Files",
+    "tabPrime": "Prime Claude"
+  }
+}