Validate an ECF Core or Micro ECF context packet import

Validates local context evidence for onboarding only. Accepted evidence includes context packet, source map, policy summary, and deployment preview, Agent OS import, or harness data. ECF Compile Stage evidence such as evidence units, page/tree indexes, retrieval plans, grounding eval, context compile readiness, and context index readiness is preserved when present so the Launch panel can show context readiness without enabling live effects. Successful imports point to the Triptych Launch Plan preview as the next step and return explicit no-spend, no-provisioning, no-wallet, no-publish, and no-x402 safety boundaries. The import does not launch an agent.