Migrate from Vite to Next.js 15 with SSR

- Replace Vite + React Router with Next.js 15 App Router
- Implement i18n with next-intl (URL-based: /de, /en, /sr)
- Add SSR/SSG for all pages (48 static pages generated)
- Setup Supabase SSR client for auth
- Migrate all pages: Home, About, Portfolio, Blog, Contact, Login, Dashboard, Imprint, Privacy, Terms
- Add Docker support with standalone output
- Replace i18next with next-intl JSON translations
- Use next/image for optimized images

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/i18n/locales-old/sr/pages/about/skillbar.ts

@@ -0,0 +1,13 @@
+export const skillbar = {
+    // Accessibility labels
+    ariaLabel: {
+        skillLevel: 'Nivo veštine',
+        progressBar: 'Indikator napretka'
+    },
+    // Screen reader text
+    screenReader: {
+        progress: '{{level}} procenata napretka za {{skill}}'
+    }
+} as const;
+// Tip za tipsku sigurnost
+export type SkillBarTranslations = typeof skillbar;