fix(admin): name records by translatable (mltext) fields

The record heading, breadcrumb crumb and document title took the first
plain text field only, so records named by an mltext field fell back to
the generic update message. A shared recordDisplayName helper now takes
the first text or ML field and reads its default locale, then the first
non-empty one.

admin/tests/form/formState.test.ts

@@ -11,6 +11,7 @@ import {
   panelDomId,
   presetUpdates,
   presetValue,
+  recordDisplayName,
   snapshot,
   tabDomId,
   tabOf,
@@ -271,3 +272,33 @@ describe('ML create seed and adopt merge', () => {
     expect(mergeMLValue({ en: 'Hello', pl: 'Witaj' }, ['en', 'pl'])).toEqual({ en: 'Hello', pl: 'Witaj' })
   })
 })
+
+describe('recordDisplayName', () => {
+  const field = (name: string, type: string): FormField => ({ ...formField('name'), name, type })
+  const text = field('name', 'text')
+  const title = field('title', 'mltext')
+  const locales = ['en', 'pl']
+
+  it('reads a plain text value, trimmed', () => {
+    expect(recordDisplayName([text], { name: '  Anna ' }, locales)).toBe('Anna')
+    expect(recordDisplayName([text], { name: 42 }, locales)).toBe('42')
+  })
+
+  it('reads the default locale of an ML value', () => {
+    expect(recordDisplayName([title], { title: { en: 'Hello', pl: 'Cześć' } }, locales)).toBe('Hello')
+  })
+
+  it('falls back to the first non-empty locale when the default is empty', () => {
+    expect(recordDisplayName([title], { title: { en: ' ', pl: 'Cześć' } }, locales)).toBe('Cześć')
+  })
+
+  it('is empty when every locale is empty', () => {
+    expect(recordDisplayName([title], { title: { en: '', pl: '' } }, locales)).toBe('')
+    expect(recordDisplayName([title], {}, locales)).toBe('')
+  })
+
+  it('skips fields that are not text-like, in favour of a later text field', () => {
+    const fields = [field('notify', 'checkbox'), field('tags', 'relation'), title, text]
+    expect(recordDisplayName(fields, { notify: true, tags: [1], title: { en: 'Post', pl: '' }, name: 'Anna' }, locales)).toBe('Post')
+  })
+})