- Add AccountType, NormalBalance, PeriodStatus enums to schema
- Add Account model with tenant scoping, code/name/type/normalBalance/parentId
- Add AccountingPeriod model with year/month/status/closedAt/closedById
- Create ISP_CHART_OF_ACCOUNTS with 28 accounts across all 5 types (1000-5000 ranges)
- Create accounting-period.ts with getOpenPeriod, closePeriod, isDateInClosedPeriod
- Extend TENANT_SCOPED_MODELS with account and accountingPeriod
- Add full query extension blocks for account and accountingPeriod in withTenantContext
- Run migration: 20260304144656_add_accounting_models
