Sub-ticket of PLUTO-163 Adopt fleet viewport/client-env telemetry standard (Elazar directive 2026-06-20): capture ONCE PER LOGIN (not per-page/per-tuple, low volume), store role[] on the row + viewportWidth + orientation to appEvents. Pluto currently has ZERO viewport telemetry (no capture code, 0 rows 30d). Converge on Mars's schema (reference impl). Enables the docente/admin/stakeholder viewport x role cohort number that Pluto could not produce for bs-mqmxqxwop02. Coordinate column/category names with mars+venus so all 3 are uniform. · pluto