Adapter event — v0.1

The event accepted by baton detect --event and the MCP handoff_detect tool: harness identity plus optional signals and material events.

• $id: https://baton.dev/schemas/adapter-event-v0.1.json
• Source of truth: AdapterEventSchema in packages/core/src/detect/index.ts
• Download: adapter-event-v0.1.json

passthrough posture: harnesses may attach extra fields (trace ids, harness versions) and they survive round-trips.