REFACTOR(repo): simplify project structure

- Move services/nextjs/ to nextjs/
- Move Dockerfile.prod to Dockerfile at root
- Remove deploy/ folder (K8s manifests moved to K3S-HOME/web-apps)
- Remove .gitea/ workflows
- Update GitHub Actions for new structure
- Remove develop branch triggers

nextjs/i18n/routing.ts

@@ -0,0 +1,9 @@
+import { defineRouting } from 'next-intl/routing';
+import { createNavigation } from 'next-intl/navigation';
+
+export const routing = defineRouting({
+  locales: ['ko', 'en', 'de'],
+  defaultLocale: 'ko'
+});
+
+export const { Link, redirect, usePathname, useRouter } = createNavigation(routing);