Sub-ticket of MARS-369 Telemetry-gap sweep+fix: find+fix places where (1) HTML form validation failures aren't recorded as telemetry, (2) try/catch is missing on user actions, (3) toasts are missing on failures, (4) toasts aren't recorded as telemetry, (5) save/submit buttons fail silently without reason saved as telemetry. Goal: every user-facing failure leaves an appEvents row. Elazar 2026-07-02. · mars