feat(train-crew): implement train crew management module

- Added DTOs for creating, querying, and updating train crew members.
- Created entity for train crew members with relevant fields and enums for role, nationality, and status.
- Developed service for handling CRUD operations and ensuring no duplicate crew members.
- Implemented controller to manage API endpoints for train crew operations.
- Integrated permissions for viewing, creating, updating, and deleting train crew members.
- Added frontend components for displaying, adding, editing, and deleting train crew members.
- Established API service for interacting with the train crew backend.
- Updated routing and sidebar to include train crew management section.

apps/edr-freight-api/src/modules/train-crew/entities/train-crew-member.entity.ts

@@ -0,0 +1,69 @@
+import { Column, Entity, Index } from 'typeorm';
+import { BaseEntity } from '@edr/api-common';
+
+/**
+ * On-board role a crew member is rostered for. Mirrors the crew composition
+ * rules in ITLMS Rolling Stock §1.2: driving crew, the federal police security
+ * detail, technical maintenance, and the four specialized cargo roles.
+ */
+export enum TrainCrewRole {
+  TRAIN_DRIVER = 'TRAIN_DRIVER',
+  FEDERAL_POLICE = 'FEDERAL_POLICE',
+  TECHNICIAN = 'TECHNICIAN',
+  REEFER_TECHNICIAN = 'REEFER_TECHNICIAN',
+  HAZMAT_ESCORT = 'HAZMAT_ESCORT',
+  LASHING_INSPECTOR = 'LASHING_INSPECTOR',
+  LIVESTOCK_HANDLER = 'LIVESTOCK_HANDLER',
+}
+
+/**
+ * Employing country. Drives the territorial boundary in §1.1 — Djibouti train
+ * drivers operate only on the Dire Dawa – Nagad segment — and the crewing
+ * cases in §2 (Case 1 pairs 2 Ethiopian with 2 Djiboutian drivers).
+ */
+export enum TrainCrewNationality {
+  ETHIOPIAN = 'ETHIOPIAN',
+  DJIBOUTIAN = 'DJIBOUTIAN',
+}
+
+export enum TrainCrewStatus {
+  ACTIVE = 'ACTIVE',
+  INACTIVE = 'INACTIVE',
+  SUSPENDED = 'SUSPENDED',
+  ON_LEAVE = 'ON_LEAVE',
+}
+
+/**
+ * Roster of people assignable to a train. Distinct from `freight.drivers`,
+ * which is the road/last-mile truck driver register (licences, vehicle types,
+ * trip counts) — a train driver shares none of those fields.
+ */
+@Entity({ schema: 'freight', name: 'train_crew_members' })
+@Index(['role'])
+@Index(['nationality'])
+@Index(['status'])
+@Index(['isActive'])
+export class TrainCrewMember extends BaseEntity {
+  @Column({ name: 'first_name', type: 'varchar', length: 100 })
+  firstName!: string;
+
+  @Column({ name: 'last_name', type: 'varchar', length: 100 })
+  lastName!: string;
+
+  @Column({ name: 'role', type: 'varchar', length: 32 })
+  role!: TrainCrewRole;
+
+  @Column({ name: 'nationality', type: 'varchar', length: 16 })
+  nationality!: TrainCrewNationality;
+
+  @Column({
+    name: 'status',
+    type: 'varchar',
+    length: 16,
+    default: TrainCrewStatus.ACTIVE,
+  })
+  status!: TrainCrewStatus;
+
+  @Column({ name: 'is_active', type: 'boolean', default: true })
+  isActive!: boolean;
+}