feat(core): the e-mail server after Java, measured against Java

SMTP on port 25 stores mails for the domain's accounts as Java reads
them anew and tells a local sender of unknown recipients; POP3 on port
110 hands them out. The mailboxes are in the snapshot and go back into
the project. EmailRun plays four stories over the network; MailCases
feeds Java's workers without one (26 cases, de and en). 18 cases name
Java bugs that the core does not take.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

packages/core/test/mailAccounts.ts

@@ -0,0 +1,44 @@
+// The accounts of tools/java-oracle's EmailRun and MailCases (EmailRun.ACCOUNTS,
+// Java's /mailserver/konten.txt) as the model holds them: anna with a mail
+// from bob and one from carla, bob without mail.
+
+import type { EmailServerAccount } from '../src/index.js';
+
+const message = (fields: Partial<EmailServerAccount['mailbox'][number]>): EmailServerAccount['mailbox'][number] => ({
+  id: 0,
+  from: { name: null, mailAddress: null },
+  to: [],
+  cc: [],
+  bcc: [],
+  subject: '',
+  body: '',
+  isNew: true,
+  isMarkedForDeletion: false,
+  isSent: false,
+  ...fields,
+});
+
+export const MAIL_ACCOUNTS: readonly EmailServerAccount[] = [
+  {
+    username: 'anna',
+    password: 'geheim',
+    firstName: 'Anna',
+    lastName: 'Muster',
+    mailbox: [
+      message({ id: 1, from: { name: 'Bob Beispiel', mailAddress: 'bob@filius.de' }, to: [{ name: null, mailAddress: 'anna@filius.de' }], subject: 'Hallo Anna', body: 'Erste Zeile\nZweite Zeile' }),
+      message({
+        id: 2,
+        from: { name: 'Carla', mailAddress: 'carla@andere.de' },
+        to: [
+          { name: 'Anna Muster', mailAddress: 'anna@filius.de' },
+          { name: null, mailAddress: 'bob@filius.de' },
+        ],
+        cc: [{ name: null, mailAddress: 'chef@filius.de' }],
+        subject: 'Termin',
+        body: 'Morgen um 10?',
+      }),
+    ],
+  },
+  { username: 'bob', password: 'passwort', firstName: 'Bob', lastName: 'Beispiel', mailbox: [] },
+];
+