chore: Add dotenv as devDependency

Added for potential use in development scripts and testing utilities.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

package.json

@@ -49,6 +49,7 @@
     "@types/react": "latest",
     "@types/react-dom": "latest",
     "@types/three": "^0.181.0",
+    "dotenv": "^17.2.3",
     "eslint": "latest",
     "eslint-config-next": "latest",
     "jiti": "^2.6.1",