Add a read-only column showing the annual budget total from the
previous year for each category. This serves as a baseline reference
when planning the current year's budget.
- Add previousYearTotal field to BudgetYearRow type
- Fetch previous year budget entries in useBudget hook
- Display column between Category and Annual in BudgetTable
- Propagate totals through parent/subtotal/section/grand total rows
- Add i18n keys for FR ("Année préc.") and EN ("Prev. Year")
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
