fix(i18n): localize all user-facing Life OS text

public/manifest.webmanifest

@@ -1,15 +1,18 @@
 {
-  "name": "Life OS · 人生操作系统",
+  "name": "Life OS",
   "short_name": "Life OS",
-  "description": "A private personal operating system for memories, reflection, and time.",
   "id": "/",
   "start_url": "/",
   "scope": "/",
   "display": "standalone",
   "background_color": "#101216",
   "theme_color": "#111317",
-  "lang": "zh-CN",
   "icons": [
-    { "src": "/life-os-icon.svg", "sizes": "any", "type": "image/svg+xml", "purpose": "any maskable" }
+    {
+      "src": "/life-os-icon.svg",
+      "sizes": "any",
+      "type": "image/svg+xml",
+      "purpose": "any maskable"
+    }
   ]
 }