fix(fls): follow Java's formats, not Java's errors

Java stays the reference for the .fls format, but its errors are no longer
copied. The Java oracle still measures Java as it is; each deliberate
departure is named in the tests with its reason (JAVA_BUGS) and must really
depart. The corpus - what Java itself writes - still reads exactly as in
Java.

- /dns/hosts: a label may start with a digit, holds no backslash, and the
  last one is not all digits (RFC 1123, RFC 3696); A, MX and NS are read in
  any case (RFC 4343); a negative TTL is invalid, so 3600 (RFC 2181). Also
  for the e-mail server's domain.
- /mailserver/konten.txt: empty fields count (Java's StringTokenizer skips
  them and shifts the rest, so an empty password breaks the account); a
  short line alone is left out, with a warning (Java throws for the whole
  file); a message keeps an empty text or subject (Java's split loses it);
  a ";" in an unescaped subject stays in the message; CRLF lines.
- /konten.txt: the last complete line is the account, also with an empty
  address (Java takes the last line and loses the account); CRLF lines.
- Static DHCP assignments: a broken entry alone is left out (Java loses
  every entry after it).

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

packages/fls/test/topology.test.ts

@@ -19,7 +19,6 @@ import {
   type FlsNodeClass,
   type FlsTopology,
   type JavaEmailAccount,
-  type JavaFailure,
 } from '../src/index.js';
 import { EXPECTED_WARNINGS } from './expectedWarnings.js';
 import { javaEmail, javaEmailAccount } from './javaEmailNames.js';
@@ -122,9 +121,8 @@ function javaApplications(applications: FlsApplication[]): unknown[] {
     }));
 }
 
-function javaFileAccounts(accounts: JavaEmailAccount[] | JavaFailure | null): unknown {
-  if (accounts === null) return null;
-  return Array.isArray(accounts) ? accounts.map(javaEmailAccount) : `!${accounts.exception}`;
+function javaFileAccounts(accounts: JavaEmailAccount[] | null): unknown {
+  return accounts === null ? null : accounts.map(javaEmailAccount);
 }
 
 /** Java's property names, as FlsOracle.java writes them. */
@@ -370,9 +368,9 @@ describe('readTopology rules', () => {
     });
   });
 
-  it('splits static DHCP assignments at Java whitespace and stops where Java throws', () => {
-    // U+3000 separates, U+00A0 does not; the third entry has no IP, so Java
-    // throws there and the fourth is never read.
+  it('splits static DHCP assignments at Java whitespace and leaves out only a broken one', () => {
+    // U+3000 separates, U+00A0 does not; the third entry has no IP. Java
+    // throws there and never reads the fourth — an error not copied.
     const { nodes, warnings } = topologyOf(`<object class="java.util.LinkedList">${nodeItem(`<object class="filius.hardware.knoten.Rechner">
         <void property="systemSoftware"><void property="DHCPServer">
           <void property="staticAssignedAddresses"><object class="java.util.ArrayList">
@@ -393,10 +391,11 @@ describe('readTopology rules', () => {
       staticAssignedAddresses: [
         { mac: '0A:00:00:00:00:01', ip: '10.0.0.1' },
         { mac: '0A:00:00:00:00:02', ip: '10.0.0.2\u00A0x' },
+        { mac: '0A:00:00:00:00:04', ip: '10.0.0.4' },
       ],
     });
     expect(warnings).toEqual([
-      'node 1: DHCPServer: static assignment "0A:00:00:00:00:03" has no MAC and IP; Java stops reading here',
+      'node 1: DHCPServer: static assignment "0A:00:00:00:00:03" has no MAC and IP, left out',
     ]);
   });
 
@@ -462,7 +461,7 @@ describe('readTopology rules', () => {
     const { nodes } = topologyOf(`<object class="java.util.LinkedList">${nodeItem(`<object class="filius.hardware.knoten.Rechner">
         <void property="systemSoftware"><void property="installierteAnwendungen">
           ${put('filius.software.email.EmailServer', `
-            <void property="mailDomain"><string>1und1.de</string></void>
+            <void property="mailDomain"><string>a_b.de</string></void>
             <void property="listeBenutzerkonten"><void method="add"><object class="filius.software.email.EmailKonto">
               <void property="benutzername"><string>bob</string></void>
               <void property="nachname"><null/></void>
@@ -473,7 +472,7 @@ describe('readTopology rules', () => {
         </void></void></object>`)}</object>`);
     const server = nodes[0]!.system.applications![0]!;
 
-    // setMailDomain keeps "filius.de" for a domain Java's pattern rejects.
+    // setMailDomain keeps "filius.de" for a domain that is not a domain name.
     expect(server).toMatchObject({ isActive: false, mailDomain: 'filius.de' });
     expect(server.beanAccounts![0]).toMatchObject({ username: 'bob', lastName: '', firstName: '' });
     expect(server.beanAccounts![0]!.messages[0]!.sender).toEqual({ name: 'Alice', mailAddress: 'alice@senior.de' });