v0.1.0 of material_expressive

A complete expressive design system for Flutter — tokens, motion, shapes, theme generation, adaptive layouts, loading indicators, animated icons, and screen templates. Changelog excerpt: - Initial release - Design tokens: colors, typography, spacing, radius, elevation, motion, opacity, state, shapes - Shape system: rounded, squircle, organic, full - Motion system: predefined specs, page transitions, container transform - Theme generation from seed color - Token provider with context extensions - Adaptive spacing (phone/tablet/desktop) - Components: surfaces, state layer, loading indicators, animated icons - Templates: settings, login, profile, dashboard, search, chat, list, medi[...]