Enhance playtime formatting to include hours and minutes; update localization for time in English and Chinese

src/locales/en.json

@@ -51,13 +51,9 @@
     "joinForum": "Join Forum",
     "viewFriends": "View Friends"
   },
-  "activity": {
-    "title": "Recent Activity",
-    "topPlayers": "Top Players by Playtime",
-    "serverInfo": "Server Info",
-    "serverStatus": "Status: Online ✓",
-    "currentMap": "Map: de_dust2",
-    "nextRestart": "Restart: 6h 30m"
+  "time": {
+    "hours": "h",
+    "minutes": "m"
   },
   "footer": {
     "community": "🎯 CS Community",