add company stamp upload functionality for contract signing

- Introduced StampUpload component for uploading company stamp images.
- Integrated stamp upload in contract signing modal, supporting PNG and JPG formats.
- Implemented validation for file type and size (max 5 MB).
- Added visual feedback for drag-and-drop functionality.
- Updated contract-related pages to handle duplicate contract alerts and pricing notices.
- Enhanced contract expiry management with a nightly sweep service.
- Added unit tests for new features and updated existing tests for contract handling.

apps/edr-freight-api/src/modules/rule-engine/entities/rate.entity.ts

@@ -34,6 +34,9 @@ export type RateStatus = typeof RATE_STATUSES[number];
 export const RATE_UNITS = [
   'PER_WAGON',
   'PER_TON',
+  // Break-bulk commodities are counted, not weighed (cargo_types.unit_of_measure
+  // = PER_ITEM) — their rates bill per item off the same booking quantity field.
+  'PER_ITEM',
   'PER_CONTAINER',
   'PER_KM',
   'PER_INVOICE',