- Introduced `quantity_math.gd` for arithmetic operations including allocation, normalization, and accumulation of quantities without scene tree dependencies.
- Created `entity_catalog.gd` to manage entity definitions, groups, and event indexes, ensuring separation from simulation state and UI.
- Implemented `item_presentation.gd` for read-only projections of simulation state, handling amounts and unlock conditions for UI elements.
- Updated `civilization_evolution.gd` and `civilization_state.gd` to utilize new quantity math functions, improving code clarity and maintainability.
- Enhanced tests in `test_quantity_catalog.gd` to validate new functionality and ensure correctness of mathematical operations.
- Revised documentation to reflect changes in module structure and functionality.
Kirill