init: scaffold complet Sakuin — backend NestJS + frontend SvelteKit + CI/CD + deploy VPS

Backend: 5 modules (auth, user, work, list, health), AniList GraphQL proxy,
SuperOAuth PKCE introspection, XP system, migrations TypeORM.
Frontend: SvelteKit adapter-node, PWA manifest, dark theme, pages home/search/list/profile/callback.
Infra: CI/CD Gitea vps-runner, Apache vhost SSL, pm2 sakuin-backend + sakuin-frontend, port 4002.
License: BSL 1.1 (Apache 2.0 en 2028).

backend/.env.example

@@ -0,0 +1,20 @@
+# Sakuin Backend
+PORT=4002
+
+# Database
+DB_HOST=localhost
+DB_PORT=3306
+DB_USERNAME=
+DB_PASSWORD=
+DB_DATABASE=sakuin
+
+# SuperOAuth
+SUPEROAUTH_URL=https://superoauth.tetardtek.com
+SUPEROAUTH_CLIENT_ID=sakuin
+SUPEROAUTH_CLIENT_SECRET=
+
+# AniList (public API — no auth required for search)
+ANILIST_API_URL=https://graphql.anilist.co
+
+# Frontend URL (CORS)
+FRONTEND_URL=http://localhost:5173