feat(editor): F4.6b the command line on a computer's desktop

A new oracle, TerminalWindowRun, types into Java's own command line
window: the window writes each line after its prompt, takes a blank
line, cls, reset and exit itself, keeps the lines for the arrow keys,
and keeps its text, history and working directory over a stop and a
start.

The room now holds a command line window per computer for everyone
(TerminalWindow), kept over stops; the protocol carries its lines and
the one way to read them (terminalScreen); the core goes on in the
working directory of the run before (continueIn). The desktop opens
programs in Java's frame, and the command line works with keyboard and
finger: grey on black, the prompt hidden while a command runs, history,
chips for the commands, Ctrl+C. The room's failure is now tested in the
browser.

Fixed: the room handed the engine the wall clock with fractions of a
millisecond, and a ping hung after its first timeout. The engine and
the room count whole milliseconds, as Java's clock does.

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

packages/editor/src/Editor.tsx

@@ -20,9 +20,10 @@ import { Palette, type PaletteKind } from './design/Palette.js';
 import { RouterDialog } from './design/RouterDialog.js';
 import { DeviceSheet } from './sheet/DeviceSheet.js';
 import { DesktopWindow } from './desktop/DesktopWindow.js';
+import type { DesktopProgram } from './desktop/programs.js';
 import { useTranslate } from './i18n/i18n.js';
 import { ModeBar } from './simulation/ModeBar.js';
-import { useSimulation, type Simulation, type SimHostFactory } from './simulation/useSimulation.js';
+import { useSimulation, type SimHostFactory } from './simulation/useSimulation.js';
 
 /** The document's drawing, read anew after every change. */
 export function useTopologyView(doc: Y.Doc): TopologyView {
@@ -79,6 +80,7 @@ interface OpenDesktop {
   readonly x: number;
   readonly y: number;
   readonly z: number;
+  readonly program: DesktopProgram | null;
 }
 
 /** Brings a desktop to the top by its stacking, not its place in the page: moved in the page, it would lose the press on it. */
@@ -87,13 +89,6 @@ const toFront = (open: readonly OpenDesktop[], id: string): readonly OpenDesktop
   return open.some((each) => each.id === id && each.z === top) ? open : open.map((each) => (each.id === id ? { ...each, z: top + 1 } : each));
 };
 
-/** A desktop that watches its computer's network while it is shown. */
-function WatchedDesktop({ simulation, ...props }: Omit<Parameters<typeof DesktopWindow>[0], 'settings'> & { readonly simulation: Simulation }) {
-  const { watch } = simulation;
-  useEffect(() => watch([`node:${props.id}`]), [watch, props.id]);
-  return <DesktopWindow {...props} settings={simulation.nodes.get(props.id)} />;
-}
-
 export function Editor({ doc, createSimHost }: { readonly doc: Y.Doc; readonly createSimHost?: SimHostFactory }) {
   const t = useTranslate();
   const view = useTopologyView(doc);
@@ -146,7 +141,7 @@ export function Editor({ doc, createSimHost }: { readonly doc: Y.Doc; readonly c
     setDesktops((open) => {
       if (open.some((each) => each.id === id)) return toFront(open, id);
       // Java stacks a desktop that does not fit beside the others a little further on.
-      return [...open, { id, x: 24 + 24 * open.length, y: 76 + 24 * open.length, z: Math.max(0, ...open.map((each) => each.z)) + 1 }];
+      return [...open, { id, x: 24 + 24 * open.length, y: 76 + 24 * open.length, z: Math.max(0, ...open.map((each) => each.z)) + 1, program: null }];
     });
   }, []);
 
@@ -305,7 +300,7 @@ export function Editor({ doc, createSimHost }: { readonly doc: Y.Doc; readonly c
           </div>
           {simulating
             ? desktops.map((desktop) => (
-                <WatchedDesktop
+                <DesktopWindow
                   key={desktop.id}
                   simulation={simulation}
                   doc={doc}
@@ -314,6 +309,8 @@ export function Editor({ doc, createSimHost }: { readonly doc: Y.Doc; readonly c
                   x={desktop.x}
                   y={desktop.y}
                   z={desktop.z}
+                  program={desktop.program}
+                  onProgram={(program) => setDesktops((open) => open.map((each) => (each.id === desktop.id ? { ...each, program } : each)))}
                   onMove={(x, y) => setDesktops((open) => open.map((each) => (each.id === desktop.id ? { ...each, x, y } : each)))}
                   onFront={() => setDesktops((open) => toFront(open, desktop.id))}
                   onClose={() => setDesktops((open) => open.filter((each) => each.id !== desktop.id))}