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/modules/audit/dto/audit-log-query.dto.ts

@@ -0,0 +1,64 @@
+import { ApiPropertyOptional } from '@nestjs/swagger';
+import { Transform } from 'class-transformer';
+import { IsBooleanString, IsIn, IsISO8601, IsOptional, IsString, IsUUID, MaxLength } from 'class-validator';
+
+import { PaginationQueryDto } from '../../../common/dto/pagination-query.dto';
+
+const AUDITED_METHODS = ['POST', 'PUT', 'PATCH', 'DELETE'] as const;
+
+/**
+ * Filters for the audit log read endpoint.
+ *
+ * Extends the shared pagination DTO so page/pageSize behave (and are capped)
+ * exactly as they do on every other list endpoint.
+ */
+export class AuditLogQueryDto extends PaginationQueryDto {
+  @ApiPropertyOptional({
+    description: 'Entity type, e.g. "Contract", "Booking", "Locomotive".',
+    example: 'Contract',
+  })
+  @IsOptional()
+  @IsString()
+  @MaxLength(50)
+  type?: string;
+
+  @ApiPropertyOptional({ description: 'IAM id of the acting backoffice user.' })
+  @IsOptional()
+  @IsUUID()
+  userId?: string;
+
+  @ApiPropertyOptional({ enum: AUDITED_METHODS })
+  @IsOptional()
+  @Transform(({ value }) => String(value).toUpperCase())
+  @IsIn([...AUDITED_METHODS])
+  method?: string;
+
+  @ApiPropertyOptional({ description: 'Id of the affected record.' })
+  @IsOptional()
+  @IsString()
+  @MaxLength(64)
+  resourceId?: string;
+
+  @ApiPropertyOptional({
+    description: 'Filter by outcome: true = succeeded, false = failed.',
+  })
+  @IsOptional()
+  @IsBooleanString()
+  isSuccess?: string;
+
+  @ApiPropertyOptional({
+    description: 'Inclusive start of the range (ISO 8601).',
+    example: '2026-01-01T00:00:00.000Z',
+  })
+  @IsOptional()
+  @IsISO8601()
+  from?: string;
+
+  @ApiPropertyOptional({
+    description: 'Inclusive end of the range (ISO 8601).',
+    example: '2026-01-31T23:59:59.999Z',
+  })
+  @IsOptional()
+  @IsISO8601()
+  to?: string;
+}