Move the AritmoLab provider (Qwen) into harness/.pi/extensions/ so it is auto-discovered only when Pi runs with cwd=harness, keeping it project-local. GLM (~/.pi/agent/models.json) and DeepSeek (built-in) stay user-wide. File is .js (not .mjs) because Pi extension auto-discovery matches only /\.(ts|js)$/. Removes the gemma4-26b-a4b model (404 at the endpoint) from both the provider and the model-matrix default list. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>