Add mapping tests for the five event classes (verdict resolution,
severity grading, the value-pinned-to-1 contract, unknown-codepoint
fallback, and that a continuous measurement never gets a classification),
the awareness-card gating + device-verdict framing + disclaimer presence,
and the events route narrowing + empty-state contract. Extend the enum,
chart-token and Coach-gate drift guards for the new event types.