feat: add news section with admin editor and public display

- NewsItem type with title, text, date, optional image and link
- Admin page at /admin/news with image upload and auto-date
- Public section between Pricing and FAQ, hidden when empty
- Nav link auto-hides when no news items exist

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/app/page.tsx

@@ -5,6 +5,7 @@ import { Classes } from "@/components/sections/Classes";
 import { MasterClasses } from "@/components/sections/MasterClasses";
 import { Schedule } from "@/components/sections/Schedule";
 import { Pricing } from "@/components/sections/Pricing";
+import { News } from "@/components/sections/News";
 import { FAQ } from "@/components/sections/FAQ";
 import { Contact } from "@/components/sections/Contact";
 import { BackToTop } from "@/components/ui/BackToTop";
@@ -33,6 +34,7 @@ export default function HomePage() {
         <MasterClasses data={content.masterClasses} />
         <Schedule data={content.schedule} classItems={content.classes.items} />
         <Pricing data={content.pricing} />
+        <News data={content.news} />
         <FAQ data={content.faq} />
         <Contact data={content.contact} />
         <BackToTop />