Removed MuiColorSchemeSync: it called MUI setMode which ALSO wrote data-theme, fighting ThemeContext (the other writer) → theme flip-flop loop. ThemeContext is now the sole owner; MUI's cssVariables CSS (scoped by [data-theme]) applies from the attribute, no JS bridge needed. New animated ThemeToggle kit button (sun/moon crossfade+rotate) replaces the static AppShell toggle. DashAttendanceToday avatars now solid-fill + white initials (matches StatCard/activity badges).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
