- theme.ts: colorScheme → data-tg-theme on <html>; header_bg_color 0-1 luminance fallback
(T-03-11 — Telegram hex is a signal, never a consumed CSS value); applyTheme's ONLY
statement is the attribute set (Pitfall 7 / D-10, greppable invariant)
- backbutton.ts: hide() at init (one shell state), onClick is total — close() at the root,
no dead-ends (UI-SPEC §BackButton)
- safe-area.ts: env(safe-area-inset-*) probe ∪ WebApp.safeAreaInset, per-edge max,
version-gated at 8.0, applied as --safe-* custom properties on :root
- webapp.ts + backbutton/safe-area never read node_modules types;
@types/telegram-web-app stays dropped (web/package.json untouched)