fix(build): resolve web build script export error and add missing serve dependency

- Fix malformed multi-line comment in .env.test causing shell parsing failure
- Add serve@14.2.4 as dev dependency to eliminate build-time installation prompts
- Resolves "export: ' production).=': not a valid identifier" error
- Test environment builds now complete successfully without user interaction

Fixes test environment build blocking issue

package.json

@@ -246,6 +246,7 @@
     "postcss": "^8.4.38",
     "prettier": "^3.2.5",
     "rimraf": "^6.0.1",
+    "serve": "^14.2.4",
     "tailwindcss": "^3.4.1",
     "ts-jest": "^29.4.0",
     "tsx": "^4.20.4",