feat: add wagon usage computation and maintenance logging features

- Implemented  utility to calculate wagon usage metrics for train schedules.
- Created  for sending wagons to maintenance with optional notes.
- Added unit tests for train builder maintenance functionalities, including formatting train run labels and building maintenance notes.
- Developed  component for merging train schedules with detailed previews and reasons for merging.
- Introduced  component for selecting wagons with search functionality and selection limits.
- Created  for displaying and filtering audit logs, including detailed views of individual log entries.
- Added  for handling API interactions related to audit logs, including fetching logs and entity types.

apps/edr-freight-api/src/migrations/3390000000000-CreateAuditLogs.ts

@@ -0,0 +1,81 @@
+import { MigrationInterface, QueryRunner } from "typeorm";
+
+/**
+ * Backoffice audit trail for every state-changing freight endpoint.
+ *
+ * No `updated_at` / `deleted_at` columns, unlike every other table here: audit
+ * rows are insert-only evidence. A soft-delete column would let an actor erase
+ * their own trail and TypeORM would then hide those rows from default queries
+ * silently — see the entity comment.
+ *
+ * `user_id` intentionally carries NO foreign key to the `iam` schema.
+ * Cross-schema FKs are forbidden platform-wide, and one here would let user
+ * deletion cascade away the record of what that user did.
+ *
+ * DDL is idempotent (`IF NOT EXISTS`) because watch-mode API instances race
+ * `migrationsRun` against each other on the shared dev database.
+ */
+export class CreateAuditLogs3390000000000 implements MigrationInterface {
+  name = "CreateAuditLogs3390000000000";
+
+  public async up(queryRunner: QueryRunner): Promise<void> {
+    await queryRunner.query(`
+      CREATE TABLE IF NOT EXISTS freight.audit_logs (
+        id            uuid         NOT NULL DEFAULT gen_random_uuid(),
+        title         varchar(255) NOT NULL,
+        method        varchar(10)  NOT NULL,
+        url           text         NOT NULL,
+        route_path    varchar(255),
+        type          varchar(50)  NOT NULL,
+        is_success    boolean      NOT NULL,
+        user_id       uuid,
+        resource_id   varchar(64),
+        request       jsonb,
+        status_code   smallint,
+        error_message text,
+        user_name     varchar(150),
+        user_role     varchar(100),
+        ip_address    inet,
+        user_agent    text,
+        request_id    varchar(64),
+        duration_ms   integer,
+        created_at    timestamptz  NOT NULL DEFAULT now(),
+        CONSTRAINT "PK_audit_logs" PRIMARY KEY (id)
+      )
+    `);
+
+    // Every audit query is time-bounded, so created_at leads each index.
+    // DESC matches the "newest first" read path the controller exposes.
+    await queryRunner.query(`
+      CREATE INDEX IF NOT EXISTS "IDX_audit_logs_created_at"
+        ON freight.audit_logs (created_at DESC)
+    `);
+    await queryRunner.query(`
+      CREATE INDEX IF NOT EXISTS "IDX_audit_logs_user_id_created_at"
+        ON freight.audit_logs (user_id, created_at DESC)
+    `);
+    await queryRunner.query(`
+      CREATE INDEX IF NOT EXISTS "IDX_audit_logs_type_created_at"
+        ON freight.audit_logs (type, created_at DESC)
+    `);
+    await queryRunner.query(`
+      CREATE INDEX IF NOT EXISTS "IDX_audit_logs_type_resource_id"
+        ON freight.audit_logs (type, resource_id)
+    `);
+    await queryRunner.query(`
+      CREATE INDEX IF NOT EXISTS "IDX_audit_logs_route_path_created_at"
+        ON freight.audit_logs (route_path, created_at DESC)
+    `);
+    // Failures are a small slice of the table but carry the security signal
+    // (403s especially), so they get their own partial index.
+    await queryRunner.query(`
+      CREATE INDEX IF NOT EXISTS "IDX_audit_logs_failures"
+        ON freight.audit_logs (created_at DESC)
+        WHERE is_success = false
+    `);
+  }
+
+  public async down(queryRunner: QueryRunner): Promise<void> {
+    await queryRunner.query(`DROP TABLE IF EXISTS freight.audit_logs`);
+  }
+}

apps/edr-freight-api/src/migrations/3400000000000-TransferRequestPreferredWagons.ts

@@ -0,0 +1,29 @@
+import { MigrationInterface, QueryRunner } from 'typeorm';
+
+/**
+ * Wagons the requester specifically asked for. A transfer request stays
+ * count-driven (`quantity` is what must be delivered), but a requester who
+ * picked wagons off the yard desk now records WHICH ones — OCC sees the numbers
+ * on the queue and the fulfil picker pre-selects them.
+ *
+ * Stored as a uuid[] column rather than a join table: the list is read and
+ * written whole, never queried by wagon, and a preference carries no lifecycle
+ * of its own (no FK — a purged wagon simply drops out of the display).
+ */
+export class TransferRequestPreferredWagons3400000000000
+  implements MigrationInterface
+{
+  public async up(queryRunner: QueryRunner): Promise<void> {
+    await queryRunner.query(`
+      ALTER TABLE freight.wagon_transfer_requests
+        ADD COLUMN IF NOT EXISTS preferred_wagon_ids uuid[]
+    `);
+  }
+
+  public async down(queryRunner: QueryRunner): Promise<void> {
+    await queryRunner.query(`
+      ALTER TABLE freight.wagon_transfer_requests
+        DROP COLUMN IF EXISTS preferred_wagon_ids
+    `);
+  }
+}

apps/edr-freight-api/src/migrations/3410000000000-ScheduleVoyageNumber.ts

@@ -0,0 +1,28 @@
+import { MigrationInterface, QueryRunner } from 'typeorm';
+
+/**
+ * Voyage number for one departure.
+ *
+ * `train_number` already exists on a schedule (the run number), but operations
+ * also quote a VOYAGE number — the sailing/run identifier yards and customs use
+ * for a specific departure. It belongs on the schedule, not the built train: one
+ * train serves many departures and each carries its own voyage.
+ *
+ * Nullable and un-indexed: it is display/reference data typed by staff, not a
+ * lookup key, and older schedules simply have none.
+ */
+export class ScheduleVoyageNumber3410000000000 implements MigrationInterface {
+  public async up(queryRunner: QueryRunner): Promise<void> {
+    await queryRunner.query(`
+      ALTER TABLE freight.train_schedules
+        ADD COLUMN IF NOT EXISTS voyage_number varchar(20)
+    `);
+  }
+
+  public async down(queryRunner: QueryRunner): Promise<void> {
+    await queryRunner.query(`
+      ALTER TABLE freight.train_schedules
+        DROP COLUMN IF EXISTS voyage_number
+    `);
+  }
+}