Create a bluetooth smart ring flex circuit using tscircuit. Deliver the tscircuit source, a rendered circuit/PCB preview and a concise component list. Explain any assumptions and validation limits; distinguish a concept design from manufacturing-ready hardware. Source: https://x.com/seveibar/status/2105043390576590978 (29.5K views, 153 likes observed 2026-10-01). Adapted reproduction brief based on the public post; not the original verbatim prompt. Compare the current Evals-selected models, not the original model versions.