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/migrations/3850000000000-TrainCrewMembers.ts

@@ -0,0 +1,68 @@
+import { MigrationInterface, QueryRunner } from 'typeorm';
+
+/**
+ * Roster of people assignable to a train (ITLMS Rolling Stock §1.2 crew
+ * composition). Separate from freight.drivers, which registers road/last-mile
+ * truck drivers and shares none of these fields.
+ *
+ * Role and nationality are stored as varchar rather than PG enums so adding a
+ * crew role later is an application change, not a type migration. The partial
+ * unique index keys on name + role — the roster has no employee number yet, so
+ * that is the only identity available to block an accidental re-entry; it is
+ * scoped to live rows so a soft-deleted member does not hold the name hostage.
+ */
+export class TrainCrewMembers3850000000000 implements MigrationInterface {
+  name = 'TrainCrewMembers3850000000000';
+
+  public async up(queryRunner: QueryRunner): Promise<void> {
+    await queryRunner.query(`
+      CREATE TABLE IF NOT EXISTS freight.train_crew_members (
+        id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
+        first_name varchar(100) NOT NULL,
+        last_name varchar(100) NOT NULL,
+        role varchar(32) NOT NULL,
+        nationality varchar(16) NOT NULL,
+        status varchar(16) NOT NULL DEFAULT 'ACTIVE',
+        is_active boolean NOT NULL DEFAULT true,
+        created_at timestamptz NOT NULL DEFAULT now(),
+        updated_at timestamptz NOT NULL DEFAULT now(),
+        deleted_at timestamptz,
+        CONSTRAINT chk_train_crew_role CHECK (role IN (
+          'TRAIN_DRIVER','FEDERAL_POLICE','TECHNICIAN','REEFER_TECHNICIAN',
+          'HAZMAT_ESCORT','LASHING_INSPECTOR','LIVESTOCK_HANDLER'
+        )),
+        CONSTRAINT chk_train_crew_nationality CHECK (nationality IN (
+          'ETHIOPIAN','DJIBOUTIAN'
+        )),
+        CONSTRAINT chk_train_crew_status CHECK (status IN (
+          'ACTIVE','INACTIVE','SUSPENDED','ON_LEAVE'
+        ))
+      )
+    `);
+    await queryRunner.query(`
+      CREATE INDEX IF NOT EXISTS idx_train_crew_members_role
+        ON freight.train_crew_members (role)
+    `);
+    await queryRunner.query(`
+      CREATE INDEX IF NOT EXISTS idx_train_crew_members_nationality
+        ON freight.train_crew_members (nationality)
+    `);
+    await queryRunner.query(`
+      CREATE INDEX IF NOT EXISTS idx_train_crew_members_status
+        ON freight.train_crew_members (status)
+    `);
+    await queryRunner.query(`
+      CREATE INDEX IF NOT EXISTS idx_train_crew_members_is_active
+        ON freight.train_crew_members (is_active)
+    `);
+    await queryRunner.query(`
+      CREATE UNIQUE INDEX IF NOT EXISTS uq_train_crew_members_name_role
+        ON freight.train_crew_members (lower(first_name), lower(last_name), role)
+        WHERE deleted_at IS NULL
+    `);
+  }
+
+  public async down(queryRunner: QueryRunner): Promise<void> {
+    await queryRunner.query(`DROP TABLE IF EXISTS freight.train_crew_members`);
+  }
+}