feat(evals): SQLite store + self-contained HTML dashboard

evals.db (tier results) + experiments.db (26-row verdict ledger) built
from JSON via the sqlite3 CLI; dashboard.html is dependency-free
(embedded JSON + inline SVG: orthogonality scatter, scorecard, routing,
probes, adversarial cards, experiments panel).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>