feat(editor): F4.6a simulation mode and a computer's desktop

Java's mode buttons start and stop the room, now in a worker of the
editor's page (LocalSimHost), with Java's speed slider. While the
simulation runs the design is locked as in Java: no palette, no sheet,
nothing moves, no undo. Cables that carry a frame light up in Java's
green, and a tap on a computer opens its desktop: Java's title, the
software installation first, then the installed programs in the order
of Java's list for the language, a taskbar with the network icon and
the network as the simulation runs it. The room sends that over a new
topic, node:<id>. Desktops stay over a return to the design and show
again at the next start. The programs' windows follow from F4.6b.

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

packages/sim/test/localSimHost.test.ts

@@ -117,8 +117,8 @@ describe('the simulation in a worker of the page', () => {
     const host = new LocalSimHost(doc, channel.port1 as unknown as Port, () => channel.port1.close());
     const got: HostMessage[] = [];
     host.onMessage((message) => got.push(message));
-    channel.port2.postMessage({ type: 'host', message: { v: 1, kind: 'node', id: 'x' } });
-    expect(await until(() => got[0])).toEqual({ v: 1, kind: 'error', code: 'unknownKind', detail: 'kind node' });
+    channel.port2.postMessage({ type: 'host', message: { v: 1, kind: 'nodes', id: 'x' } });
+    expect(await until(() => got[0])).toEqual({ v: 1, kind: 'error', code: 'unknownKind', detail: 'kind nodes' });
     host.close();
     channel.port2.close();
   });

packages/sim/test/room.test.ts

@@ -306,4 +306,28 @@ describe('a simulation room', () => {
     expect(ofKind(got, 'error')).toHaveLength(1);
     expect(ofKind(got, 'state').at(-1)).toMatchObject({ mode: 'simulation' });
   });
+
+  it("sends a computer's network as it runs, anew when DHCP changes it, and nothing before a start", () => {
+    const { got, send, run, node } = setUp(exampleDoc('java-examples/einfaches_rechnernetz_komplett.fls'));
+    const notebook = node('Notebook 1');
+    const server = node('Server');
+    send({ kind: 'sub', topics: [`node:${notebook.id}`, `node:${server.id}`] });
+    expect(ofKind(got, 'node')).toEqual([]);
+    send({ kind: 'start' });
+    run(20_000);
+    const sent = ofKind(got, 'node').filter((each) => each.node === notebook.id);
+    expect(sent.length).toBeGreaterThanOrEqual(2);
+    expect(sent.at(-1)!.settings).toMatchObject({ subnetMask: '255.255.255.0', dnsServer: '192.168.0.100', macAddress: expect.stringMatching(/^([0-9A-F]{2}:){5}[0-9A-F]{2}$/) });
+    expect(sent.at(-1)!.settings.ipAddress).toMatch(/^192\.168\.0\.\d+$/);
+    // Sent when it changes, not every tick.
+    expect(new Set(sent.map((each) => JSON.stringify(each.settings))).size).toBe(sent.length);
+    expect(ofKind(got, 'node').filter((each) => each.node === server.id).map((each) => each.settings)).toEqual([
+      { ipAddress: '192.168.0.100', subnetMask: '255.255.255.0', defaultGateway: '', dnsServer: '192.168.0.100', macAddress: expect.any(String) },
+    ]);
+    // A client that subscribes again gets it again.
+    const before = got.length;
+    send({ kind: 'sub', topics: [`node:${server.id}`] });
+    expect(ofKind(got.slice(before), 'node')).toHaveLength(1);
+  });
 });
+