feat(pagination): raise the page-size ceiling to 500

Rows-per-page was capped at 100 in three independent places: @Max on
PaginationQueryDto, the same @Max repeated on ListWagonsQueryDto (which does
not extend the base), and MAX_PAGE_SIZE in pagination.util. The first two
reject with a 400, the third silently truncates, so a larger page size had to
be lifted in all three or the endpoints that opted in would refuse it --
train schedules, routes, locomotives, wagons, audit, rule engine, built
trains, batch board and the rest.

No service overrides maxPageSize, so the util constant is the effective cap
everywhere it is reached.

Adds a spec pinning the three together: 500 validates, 501 rejects, and the
util returns take: 500 rather than truncating. A fourth copy of the number
lives in the backoffice data-table footer and is noted there.

apps/edr-freight-api/src/common/dto/page-size-cap.spec.ts

@@ -0,0 +1,32 @@
+import { plainToInstance } from 'class-transformer';
+import { validateSync } from 'class-validator';
+
+import { PaginationQueryDto } from './pagination-query.dto';
+import { ListWagonsQueryDto } from '../../modules/wagons/dto/list-wagons-query.dto';
+import { normalizePagination } from '../utils/pagination.util';
+
+/**
+ * The page-size ceiling is stated in three places that must agree: `@Max` on
+ * PaginationQueryDto, the same `@Max` repeated on ListWagonsQueryDto (which
+ * doesn't extend it), and `MAX_PAGE_SIZE` in pagination.util. A fourth copy
+ * lives outside this package — `MAX_PAGE_SIZE` in @edr/ui-common's data-table
+ * footer, which is what actually asks for the number. Drift between any of
+ * them shows up as a 400 on the largest rows-per-page option, so pin them.
+ */
+const errorsFor = (cls: any, pageSize: unknown) =>
+  validateSync(plainToInstance(cls, { pageSize }), { whitelist: false });
+
+describe('page size ceiling', () => {
+  it.each([PaginationQueryDto, ListWagonsQueryDto])('accepts 500 on %p', (cls) => {
+    expect(errorsFor(cls, 500)).toHaveLength(0);
+  });
+
+  it.each([PaginationQueryDto, ListWagonsQueryDto])('rejects 501 on %p', (cls) => {
+    expect(errorsFor(cls, 501)).not.toHaveLength(0);
+  });
+
+  it('does not truncate 500 in the service-side clamp', () => {
+    expect(normalizePagination({ page: 1, pageSize: 500 }).take).toBe(500);
+    expect(normalizePagination({ page: 1, pageSize: 501 }).take).toBe(500);
+  });
+});

apps/edr-freight-api/src/common/dto/pagination-query.dto.ts

@@ -19,12 +19,18 @@ export class PaginationQueryDto {
   @Min(1)
   page?: number;
 
-  @ApiPropertyOptional({ default: 20, minimum: 1, maximum: 100 })
+  /**
+   * Ceiling is 500, matching `MAX_PAGE_SIZE` in `common/utils/pagination.util.ts`
+   * and the backoffice table footer's largest option. The three have to agree:
+   * a lower value here turns the footer's top preset into a 400, a higher one
+   * lets a request through that the util then silently truncates.
+   */
+  @ApiPropertyOptional({ default: 20, minimum: 1, maximum: 500 })
   @IsOptional()
   @Transform(({ value }) => parseInt(String(value), 10) || 20)
   @IsInt()
   @Min(1)
-  @Max(100)
+  @Max(500)
   pageSize?: number;
 
   @ApiPropertyOptional({

apps/edr-freight-api/src/common/utils/pagination.util.ts

@@ -20,7 +20,12 @@ export interface NormalizedPage {
 }
 
 const DEFAULT_PAGE_SIZE = 20;
-const MAX_PAGE_SIZE = 100;
+/**
+ * Must stay in step with `@Max` on `PaginationQueryDto.pageSize` and with
+ * `MAX_PAGE_SIZE` in the backoffice's data-table footer — the DTO rejects,
+ * this clamps, and the footer is what actually asks for the number.
+ */
+const MAX_PAGE_SIZE = 500;
 
 /** Clamp raw query values into a safe page window (page ≥ 1, pageSize capped). */
 export function normalizePagination(

apps/edr-freight-api/src/modules/wagons/dto/list-wagons-query.dto.ts

@@ -72,12 +72,14 @@ export class ListWagonsQueryDto {
   @Min(1)
   page?: number;
 
-  @ApiPropertyOptional({ default: 10, minimum: 1, maximum: 100 })
+  // 500 to match PaginationQueryDto — this DTO doesn't extend it, so the
+  // ceiling has to be repeated here or the wagons list alone rejects at 100.
+  @ApiPropertyOptional({ default: 10, minimum: 1, maximum: 500 })
   @IsOptional()
   @Type(() => Number)
   @IsInt()
   @Min(1)
-  @Max(100)
+  @Max(500)
   pageSize?: number;
 
   @ApiPropertyOptional({ description: 'Registered on or after this day (YYYY-MM-DD)' })