- Add units + unit_translations tables with FK constraints on products and ingredient_mappings
- Normalize products.unit from Russian strings (г, кг) to English codes (g, kg)
- Load units at startup (in-memory registry) and serve via GET /units (language-aware)
- Replace hardcoded _units lists and _mapUnit() functions in Flutter with unitsProvider FutureProvider
- Re-fetches automatically when language changes
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Switch AppColors to iOS system palette (007AFF blue, F2F2F7 grouped
background, separator, label hierarchy) and rewrite AppTheme with
iOS-inspired Material 3 tokens (no elevation, negative letter-spacing,
50px buttons, 12px radii). Replace removed primaryLight/accent references
in recipe screens with primary.withValues(alpha:0.15) and primary.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>