Get survey analytics

Survey step analytics from ClickHouse (survey_events), Typeform-style. Query from, to (YYYY-MM-DD, UTC, inclusive; default the last 30 days, at most 400), version, channel, device (phone|tablet|desktop), interval (day|week), tz (IANA zone for the weekday × hour heatmap). Returns { available, range, header: { views, uniqueViews, starts, submissions, completionRate, startRate, avgTimeToCompleteMs, welcomeViews, welcomeStartRate } (each { value, previous, byDevice }), funnel, worstStepBlockId, dismissed, timing, backNavigation, closePoints, series, breakdowns, heatmap, versions, score, reminders, email, sources, quality }. available: false when no events were recorded in the range. Cached 60 seconds.