Replace ~3500L admin.js monolith with thin orchestrator (~700L) +
14 IIFE-wrapped per-section modules under /js/admin/sections/.
Section modules expose AdminSections.<name>.init/reload (lazy init via
switchTab/router) and re-expose onclick handlers via window.X for
backward compat. Shared helpers (MODES/DIFFS, fmtDate, pctClass,
renderMath, qTypeBadge, pagination) live in /js/admin/_shared.js
exposed on window.AdminCtx.
switchTab now dispatches to AdminSections via ROUTE_TO_SECTION map;
non-extracted system tabs (topics/audit/errors/health/classroom/avatars)
remain inline in admin.js. user-panel overlay markup untouched — Phase 6
will remove it.
Maxim Dolgolyov
92030b462c