feat(cms): clarify sponsor ordering

tests/int/partners-admin-ordering.int.spec.ts

@@ -0,0 +1,48 @@
+import type { Field, NumberField, NumberFieldSingleValidation } from 'payload'
+import { describe, expect, it } from 'vitest'
+
+import { Partners } from '@/collections/Partners'
+
+function partnerField(name: string): Field {
+  const field = Partners.fields.find((candidate) => 'name' in candidate && candidate.name === name)
+  if (!field) throw new Error(`Missing Partners field: ${name}`)
+  return field
+}
+
+describe('Partners admin ordering contract', () => {
+  it('shows the title and ordering state needed for content operations', () => {
+    expect(Partners.admin?.useAsTitle).toBe('name')
+    expect(Partners.admin?.defaultColumns).toEqual([
+      'name',
+      'tier',
+      'sortOrder',
+      '_status',
+      'active',
+      'showOnHomepage',
+      'updatedAt',
+    ])
+  })
+
+  it('accepts only numeric tiers 1, 2, and 3', async () => {
+    const tierField = partnerField('tier')
+
+    expect(tierField).toMatchObject({
+      type: 'number',
+      min: 1,
+      max: 3,
+      required: true,
+      admin: { step: 1 },
+    })
+
+    const validate = (tierField as NumberField).validate as NumberFieldSingleValidation | undefined
+    expect(validate).toBeTypeOf('function')
+
+    for (const value of [1, 2, 3]) {
+      expect(await validate?.(value, {} as never)).toBe(true)
+    }
+
+    for (const value of [0, 1.5, 4, Number.NaN, null, undefined]) {
+      expect(await validate?.(value, {} as never)).toBe('Tier must be one of 1, 2, or 3.')
+    }
+  })
+})