feat(chat): add markdown rendering, fix gateway WS env vars

- Add react-markdown + remark-gfm for rich message rendering
- Assistant messages now render markdown (code blocks, lists, links, etc.)
- User messages stay as plain text
- Fix docker-compose to map GATEWAY_WS_URL from VITE_WS_URL
- Added GATEWAY_WS_TOKEN to Dokploy env vars

frontend/package.json

@@ -14,7 +14,9 @@
     "better-auth": "^1.4.17",
     "react": "^19.2.0",
     "react-dom": "^19.2.0",
+    "react-markdown": "^10.1.0",
     "react-router-dom": "^7.13.0",
+    "remark-gfm": "^4.0.1",
     "tailwindcss": "^4.1.18"
   },
   "devDependencies": {