Number Input and Paste Behaviour Improvements
Numeric inputs across Financial Calculations, Economic Calculations, Project Details, and General Assumptions now handle formatted pasted values more reliably. Money values use format-on-blur display with comma grouping, year and percentage fields avoid unwanted thousands separators, and cleared or invalid entries resolve safely without producing NaN values. Fill-forward behaviour has been preserved where intended, dirty state tracking has been tightened, macro-economic rates now round consistently without adding new bounds, and result/report calculations have been hardened against legacy non-finite values.
