Feature 4: Webinterface — React-Frontend, Discord-OAuth2, REST-API

- Discord-OAuth2-Login (identify-Scope, CSRF-State, signierte Session-Cookies, keine Token-Speicherung)
- REST-API: /api/devlogs (öffentlich), /api/commits (nur ADMIN_DISCORD_ID), /api/me
- React + Vite Frontend: Devlog-Archiv mit Mini-Markdown-Renderer, Commit-Tabelle, dunkles EcoGame-Theme
- Fastify liefert frontend/dist mit SPA-Fallback aus; Vite-Dev-Proxy für lokale Entwicklung
- Multi-Stage-Dockerfile (Frontend-Build im Image), neue Env-Vars in Compose + .env.example
- README: OAuth2-Setup (Redirect-URLs, Client Secret) und Frontend-Workflow

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

package.json

@@ -14,6 +14,8 @@
     "dev": "node --watch src/index.js"
   },
   "dependencies": {
+    "@fastify/cookie": "^11.1.2",
+    "@fastify/static": "^10.1.2",
     "better-sqlite3": "^12.11.1",
     "discord.js": "^14.16.3",
     "dotenv": "^16.4.7",