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/migrations/2910000000000-AddContractSignatureStamp.ts

@@ -0,0 +1,27 @@
+import { MigrationInterface, QueryRunner } from 'typeorm';
+
+/**
+ * Company stamp (seal) attached alongside the drawn signature, for both the
+ * client and the EDR side. Stored the same way the signature image is: a
+ * FileRecord on the contract (`resource: 'contracts'`, `code: 'stamp_<role>'`)
+ * referenced from the signature row.
+ *
+ * Nullable — existing signature rows predate the stamp requirement. The
+ * "both stamps recorded" gate lives in ContractTransitionService.counterSign,
+ * not in a NOT NULL constraint, so historical rows stay readable.
+ */
+export class AddContractSignatureStamp2910000000000 implements MigrationInterface {
+  name = 'AddContractSignatureStamp2910000000000';
+
+  public async up(queryRunner: QueryRunner): Promise<void> {
+    await queryRunner.query(
+      `ALTER TABLE freight.contract_signatures ADD COLUMN IF NOT EXISTS stamp_file_id uuid;`,
+    );
+  }
+
+  public async down(queryRunner: QueryRunner): Promise<void> {
+    await queryRunner.query(
+      `ALTER TABLE freight.contract_signatures DROP COLUMN IF EXISTS stamp_file_id;`,
+    );
+  }
+}