feat(fls): import the e-mail programs into the editor model

The e-mail client and server of every host come into the model (core:
EmailClientConfiguration, EmailServerConfiguration, EmailMessage), from
Java's view:

- the server's accounts are those of /mailserver/konten.txt, as Java reads
  them at every simulation start; without the file those of the bean list,
  which Java would drop;
- the client's account is that of /konten.txt; without it the first of an
  older file's kontoListe, which FILIUS 2.14 no longer reads;
- messages are numbered per program in folder order, as Swift does; the
  sent folder's are sent; a date is taken only when the file gives one.

Departures from Swift: accounts and messages stay where Swift drops what
fails its checks; first and last name stay apart; a port that is no number
is the default, with a warning. On the corpus the model matches Swift's on
all 13 files; the one Swift error is named (it numbers a mailbox's messages
as their received time and writes that into the konten.txt it rewrites).

The Swift dump now carries the e-mail state, and the file system
comparison leaves out only Swift's hidden state files (and the directories
it makes for them) instead of all of /mail, /mailserver and /peer2peer.

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

packages/fls/test/topology.test.ts

@@ -478,6 +478,27 @@ describe('readTopology rules', () => {
     expect(server.beanAccounts![0]!.messages[0]!.sender).toEqual({ name: 'Alice', mailAddress: 'alice@senior.de' });
   });
 
+  it("reads an older file's kontoListe, which FILIUS 2.14 ignores, in the order of its entries", () => {
+    const legacyAccount = (username: string) =>
+      `<void method="put"><string>${username}@senior.de</string><object class="filius.software.email.EmailKonto">
+        <void property="benutzername"><string>${username}</string></void>
+        <void property="pop3port"><string>110</string></void>
+      </object></void>`;
+    const { nodes } = topologyOf(`<object class="java.util.LinkedList">${nodeItem(`<object class="filius.hardware.knoten.Rechner">
+        <void property="systemSoftware"><void property="installierteAnwendungen">
+          <void method="put"><string>filius.software.email.EmailAnwendung</string><object class="filius.software.email.EmailAnwendung">
+            <void property="kontoListe">${legacyAccount('rechner3')}${legacyAccount('rechner4')}</void>
+          </object></void>
+        </void></void></object>`)}</object>`);
+    const client = nodes[0]!.system.applications![0]!;
+
+    expect(client.fileAccount).toBeNull();
+    expect(client.legacyAccounts!.map((account) => [account.username, account.pop3Port])).toEqual([
+      ['rechner3', '110'],
+      ['rechner4', '110'],
+    ]);
+  });
+
   it("gives a modem Java's defaults and keeps an address the file sets to null", () => {
     const { nodes } = topologyOf(`<object class="java.util.LinkedList">
         ${nodeItem('<object class="filius.hardware.knoten.Modem"/>')}