feat: Add theme switch

packages/stl/package.json

@@ -39,6 +39,9 @@
     "@ermnvldmr/eslint-config": "workspace:*",
     "@ermnvldmr/rsbuild-config": "workspace:*",
     "@rsbuild/core": "^1.2.11",
+    "@testing-library/jest-dom": "^6.9.1",
+    "@testing-library/react": "^16.3.1",
+    "@testing-library/user-event": "^14.6.1",
     "@types/react": "^19.1.2",
     "@types/react-dom": "^19.1.2",
     "@vitest/coverage-v8": "^4.0.18",