Threshold 0.1.0

Initial release of Threshold: confidence-tiered human-in-the-loop routing for TypeScript and Swift.\n\nIncludes:\n- Pure TypeScript and Swift decision cores\n- Shared golden-vector parity corpus\n- Optional queue modules with in-memory stores and decision logs\n- Dogfooding coverage for NightShift-, MAM-, and Tally-shaped routing\n- MIT license and release-ready docs