feat(rates): last-mile rate rules with bulk per-ton-km and container distance bands

- rates: min_km/max_km columns, PER_TON_KM unit, ETB|USD currency for last mile
- extend UQ_rates_pattern with band start; overlap + shape validation
- shared last-mile charge resolver; approve-dialog price estimate endpoint
- delivery-fee invoice prices via rules, falls back to vehicle price/km
- backoffice: last-mile rate form (mode, container type, band, currency)

apps/edr-freight-web/backoffice/src/constants/URLS.ts

@@ -711,6 +711,7 @@ export const URL_CONSTANTS = {
     BASE: "/last-mile-requests",
     BY_ID: (id: string) => `/last-mile-requests/${id}`,
     FREE_TRUCK_COUNT: "/last-mile-requests/free-truck-count",
+    PRICE_ESTIMATE: (id: string) => `/last-mile-requests/${id}/price-estimate`,
     APPROVE: (id: string) => `/last-mile-requests/${id}/approve`,
     REJECT: (id: string) => `/last-mile-requests/${id}/reject`,
   },