Handle FastFlowLM (FLM) image constraints for NPU inference.
- Endpoint: `http://192.168.0.143:7771/v1`
- Strict decoder: Accepts only PNG and JPEG/JPG. WebP is rejected.
- Workflow: Convert WebP upstream before FLM calls.
- Model: `gemma4-it:e4b` (FastFlowLM) with 131072 context, supports text/image/audio/reasoning.