Making Gemma 4 (e2b) production-safe with five tiny libraries

Submission for the Gemma 4 DEV Challenge . Gemma 4 ships in four sizes: 2B and 4B for edge and mobile, a 26B Mixture-of-Experts model, and a 31B dense model for servers. The big two are great. The small two are interesting for a different reason: they run on a laptop with no API key and no rate limit. The catch with small open models is reliability. Pointing a 2B model at a real task and asking for clean JSON, well-formed tool calls, and bounded behavior is where most demos fall apart. The model