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/contracts/contracts.service.ts

@@ -1,5 +1,6 @@
 import {
   BadRequestException,
+  ConflictException,
   ForbiddenException,
   Injectable,
   NotFoundException,
@@ -24,6 +25,7 @@ import { ContractListSummaryDto } from './dto/contract-list-summary.dto';
 import { Contract, CONTRACT_STATUSES, CONTRACT_CUSTOMER_EDITABLE_STATUSES } from './entities/contract.entity';
 import { ContractRoute } from './entities/contract-route.entity';
 import { ContractCargoScope } from './entities/contract-cargo-scope.entity';
+import { isEffectivelyExpired } from './utils/contract-expiry.util';
 import { FileRecord } from '../files/entities/file.entity';
 
 /** Paginated contract list: flat `total` (backoffice) + `meta` block (portal). */
@@ -155,6 +157,42 @@ export class ContractsService {
     }
   }
 
+  /**
+   * Same customer + same service type + an overlapping route already has a
+   * non-expired contract → block. A route "overlaps" if any origin/destination
+   * pair matches — good enough today since ONE_TIME and GENERAL contracts both
+   * carry a single route in practice, and still correct if that changes.
+   */
+  private async assertNoDuplicateContract(
+    companyId: string,
+    serviceTypeId: string,
+    routes: CreateContractDto['routes'],
+  ): Promise<void> {
+    const candidates = await this.contractsRepository.findDuplicateCandidates(
+      companyId,
+      serviceTypeId,
+    );
+    const duplicate = candidates.find(
+      (c) =>
+        !isEffectivelyExpired(c) &&
+        (c.routes ?? []).some((existingRoute) =>
+          routes.some(
+            (r) =>
+              r.originYardId === existingRoute.originYardId &&
+              r.destinationYardId === existingRoute.destinationYardId,
+          ),
+        ),
+    );
+    if (duplicate) {
+      const until = duplicate.contractValidUntil
+        ? duplicate.contractValidUntil.toISOString().slice(0, 10)
+        : 'its approval completes';
+      throw new ConflictException(
+        `An active contract already exists for this service type and route (${duplicate.reference}, valid until ${until}). A new request can't be submitted until it expires or is rejected/cancelled.`,
+      );
+    }
+  }
+
   /** Create a new contract (DRAFT) with its routes and cargo-scope rows. */
   async create(
     dto: CreateContractDto,
@@ -186,6 +224,9 @@ export class ContractsService {
     this.assertCargoScopeShape(dto.freightType, dto.cargoScope);
     this.assertRouteShape(dto.contractKind, dto.routes);
     await this.assertRoutesMatchDirection(dto.tradeDirection, dto.routes);
+    if (companyId) {
+      await this.assertNoDuplicateContract(companyId, dto.serviceTypeId, dto.routes);
+    }
 
     // Stamp the operational profile for portal scoping. A forwarder contract
     // pins its profile explicitly (trade direction can't tell it apart from a