feat: redesign home and register pages for cleaner overview

Rebuild the home landing layout into a streamlined, more scannable
design: a centered focused hero, feature cards, a compact stats row,
and clearer news/users sections. Rework the register page into a
balanced two-column layout with a tidier intro panel and sticky form.
Add statsArticles translation key across locale files; verified with
tsc and biome.

src/messages/sr.json

@@ -194,6 +194,7 @@
 			"statsOnline": "Онлајн",
 			"statsCitizens": "Грађани",
 			"statsRooms": "Собе",
+			"statsArticles": "Чланци",
 			"featuresAvatar": "Аватар",
 			"featuresAvatarDesc": "Направи свој јединствени изглед",
 			"featuresFurniture": "Намештај",