add quantity cap for GENERAL contracts and implement capacity tracking

- Updated ContractClearanceService and ContractsController to remove region parameter from queue method.
- Enhanced ContractsRepository to attach contract files for download and added attachContractFiles method.
- Modified ContractsService to persist cargo scope with quantity cap based on contract kind.
- Introduced quantityCap field in CreateContractCargoScopeDto and ContractCargoScope entity.
- Implemented capacity tracking in the frontend with ContractCapacityNotice component to display remaining bookable quantities.
- Updated various components and services to support new capacity features, including hooks and API calls.
- Added migration to include quantity_cap column in contract_cargo_scope table.

apps/edr-freight-api/src/modules/contracts/dto/create-contract.dto.ts

@@ -51,6 +51,17 @@ export class CreateContractCargoScopeDto {
   @IsString()
   @MaxLength(200)
   cargoFreeText?: string | null;
+
+  @ApiPropertyOptional({
+    description:
+      'GENERAL only: total bookable quantity for this line (containers per size, or tons/items for bulk). Omit for uncapped.',
+    minimum: 1,
+  })
+  @IsOptional()
+  @IsNumber()
+  @Min(1)
+  @Transform(({ value }) => (value == null || value === '' ? null : Number(value)))
+  quantityCap?: number | null;
 }
 
 /** A contracted lane (origin → destination). Routes carry NO quantity. */