## Schema (Phase_96_001)
- escalation_type / escalation_rate / escalation_tiers_json — flat or tiered annual rent increases
- utilities_mode / utilities_rent_pct / utilities_facility_pct / facility_monthly_cost — support rent%, facility-cost%, or both
- payment_due_day — configurable per-contract (default day 5)
- late_fee_bank_rate — annual bank rate for daily penalty calculation
- grace_period_months / early_termination_months — additional contract terms
- Data migration: backfills utilities_rent_pct from utilities_percentage

## Service layer
- RentalContractService: computes escalated total_amount across flat/tiered modes; handles all utilities modes; recalculates VAT and grand_total
- RentalInvoiceService: calcBase() now escalation-aware (by period); bulkGenerate skips grace months and uses payment_due_day; calcLateFee supports bank-rate daily formula
- Seeds RENTAL_LATE_FEE_BANK_RATE business rule (27.25% annual)

## UI
- contract_form: new sections for escalation (dynamic tiers table), utilities mode, payment terms, extra contract conditions; year-by-year preview
- contract_show: mode-aware utilities display, escalation card, grace/termination info
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>