EVO-54 phase 1: demo/seed data debt inventory

EVO-54 fleet umbrella (Elazar directive via pmmaster-evolutiva-cc, 2026-07-17): demo/seed data became permanent prod debt. PHASE 1 = INVENTORY ONLY, no deletes. Enumerate: (a) every isDemo/demo-* code gate (branches, feature flags, conditionals keyed on demo status) across the app; (b) every demo periodo/comision/user/practica seed row still live in prod (per mars-commons Demo Data: @demo.mars emails, batch-scoped demo images). Report back to pm-mars-cc for relay to pmmaster. Purge-vs-keep decision comes after Elazar sign-off on the combined 3-app inventory — do not delete anything this phase.