HarnessLab v0.2.0 - Trace Contract regression gates

Full Changelog: v0.1.0...v0.2.0

HarnessLab v0.1.0 - protocol workbench

First public release of HarnessLab. Includes an ordered event-sourced agent loop, live REST/SSE trace console, six-check conformance matrix, fail-closed tool policy, deterministic offline adapter, OpenAI-compatible and public DeepSeek API adapters, an optional MCP stdio bridge, and an isolated discovery boundary for the future DeepSeek Harness protocol.