feat: add CSS generation system with custom properties and ETS cache
- Create theme-primitives.css with spacing, fonts, radius scales
- Create theme-semantic.css with semantic CSS variable aliases
- Update app.css to import theme CSS files
- Add CSSGenerator module for dynamic CSS token generation
- Generates mood variables (neutral, warm, cool, dark)
- Generates typography variables (7 font combinations)
- Generates shape variables (sharp, soft, round, pill)
- Generates density variables (spacious, balanced, compact)
- Converts hex colors to HSL for flexible manipulation
- Add CSSCache GenServer with ETS table for performance
- Caches generated CSS to avoid regeneration
- Warms cache on application startup
- Provides invalidation for theme updates
- Add CSSCache to application supervision tree
- Add comprehensive tests for CSS generation (29 tests)
- Add comprehensive tests for preset validation (14 tests)
- All tests passing (58 total tests, 0 failures)
- Verified CSS generation and caching work correctly in IEx
Jamey Greenwood
878d8f63ac