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/src/importProject.ts

@@ -91,7 +91,7 @@ import {
   type TopologyNode,
   type VirtualFileContent,
 } from '@mdg-filius/core';
-import { dnsRecordsOf, javaHostsFileContent, readJavaDnsHosts } from './dnsHosts.js';
+import { dnsRecordsOf, javaHostsFileContent, readDnsHosts } from './dnsHosts.js';
 import type { FlsApplicationClass, FlsFileTree, FlsFirewall } from './systemSoftware.js';
 import type { FlsDocumentationItem, FlsInterface, FlsNode, FlsNodeClass, FlsTopology } from './topology.js';
 
@@ -420,7 +420,7 @@ function registerPrograms(source: FlsNode, node: TopologyNode, system: SystemCon
         const primary = trimmedOrEmpty(source.interfaces[0]?.ip);
         const forwarding = recursive && forwarder !== '' && forwarder !== primary;
         const hosts = javaHostsFileContent(source.system.fileSystem);
-        const records = dnsRecordsOf(readJavaDnsHosts(hosts ?? ''), (message) =>
+        const records = dnsRecordsOf(readDnsHosts(hosts ?? ''), (message) =>
           warnings.push(`node '${node.displayName}': ${message}`),
         );
         system.dnsServerConfigurations.set(