feat: F4.6g1 the echo server and the generic client windows

Oracle EchoWindowRun uses Java's echo server and client windows as a
person does; SaveAfterRunRun echo saves what Java keeps after the run.
The room takes setActive with a port, connect/disconnect/send, sends
both views and writes the server's port and the client's target back.
The editor's windows show Java's buttons, fields and lines; a port that
is no port is marked and not handed over (Java's button throws).
Core fix: an empty message (one empty segment with the push, as Java's
erstelleSegmente makes) counted as a repeat and never arrived.

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

packages/editor/test/i18n.test.ts

@@ -45,6 +45,22 @@ const FROM_JAVA: Readonly<Record<string, string>> = {
   'explorer.notImported': 'sw_fileexplorer_msg1',
   'explorer.tooLarge': 'sw_fileexplorer_msg3',
   'viewer.open': 'imageviewer_msg2',
+  'echoServer.port': 'serverbaustein_msg1',
+  'echoServer.stop': 'serverbaustein_msg2',
+  'echoServer.start': 'serverbaustein_msg3',
+  'simpleClient.address': 'clientbaustein_msg1',
+  'simpleClient.port': 'clientbaustein_msg2',
+  'simpleClient.connect': 'clientbaustein_msg3',
+  'simpleClient.message': 'clientbaustein_msg4',
+  'simpleClient.send': 'clientbaustein_msg5',
+  'simpleClient.disconnect': 'clientbaustein_msg6',
+  'simpleClient.connected': 'sw_clientbaustein_msg2',
+  'simpleClient.disconnected': 'sw_clientbaustein_msg3',
+  'simpleClient.notConnected': 'sw_clientbaustein_msg4',
+  'simpleClient.receiveFailed': 'sw_tcpsocket_msg9',
+  'simpleClient.failure.unresolved': 'sw_socket_msg1',
+  'simpleClient.failure.timedOut': 'sw_tcpsocket_msg2',
+  'simpleClient.failure.failed': 'sw_tcpsocket_msg3',
   'textEditor.new': 'texteditor_msg3',
   'textEditor.open': 'texteditor_msg4',
   'textEditor.save': 'texteditor_msg5',
@@ -269,6 +285,7 @@ const FROM_JAVA_MENDED: Readonly<Record<string, readonly [string, (java: string)
 /** Java's words around a value, as its programs join them („Verbindung zu“ + address + „hergestellt“). */
 const FROM_JAVA_JOINED: Readonly<Record<string, readonly [string, string, string]>> = {
   'server.connectionAccepted': ['sw_serveranwendung_msg4', '{address}', 'sw_serveranwendung_msg5'],
+  'simpleClient.connectionClosed': ['sw_clientbaustein_msg5', '{address}', 'sw_clientbaustein_msg6'],
   'server.connectionClosed': ['sw_servermitarbeiter_msg1', '{address}', 'sw_servermitarbeiter_msg2'],
   'emailServer.created': ['emailserver_msg22', '{name}', 'emailserver_msg23'],
   'mail.stored': ['sw_smtpmitarbeiter_msg12', '{name}', 'sw_smtpmitarbeiter_msg13'],