feat(editor): F4.5e a router's connections in the device sheet

SheetRun now clicks through Java's JConnectionsDialog with a router, a
computer and a switch cabled in the GUIContainer: a click marks a card,
the same click unmarks it, another card swaps the cables or moves the
one; "+" adds 192.168.0.10/24 up to eight cards, "-" removes the last
card with its cable down to none, and a router without a card keeps no
gateway.

The document adds, removes and swaps a router's cards (the same cables,
the same devices), Java's click logic is one function for the test and
the page, and the sheet names the address at a cable's far end. The
page "Verbindungen verwalten" shows Java's RJ45 buttons in Java's
colours with each card's far end below. Not adopted: the last card
stays. A card tab or a mark whose card is undone away falls back.

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

packages/doc/src/commands.ts

@@ -33,8 +33,12 @@ import { emptyProject, inOrder, nodeEntry, ROOTS } from './projectDoc.js';
 /** The kinds of the palette, in Java's order (GUIDesignSidebar.addComponentItemsToSidebar; the cable comes first, a tool). */
 export const PALETTE: readonly Exclude<NodeKind, 'unsupported'>[] = ['pc', 'notebook', 'networkSwitch', 'gateway', 'router', 'remoteLink'];
 
-/** A router's interfaces, as Java's dialog offers them (2 to 8, 2 when it is closed). */
-export const ROUTER_INTERFACES = { minimum: 2, maximum: 8, standard: 2 } as const;
+/**
+ * A router's interfaces, as Java's dialog offers them (2 to 8, 2 when it is
+ * closed); its connections dialog removes them down to `fewest` here (Java:
+ * none — see settings.ts).
+ */
+export const ROUTER_INTERFACES = { minimum: 2, maximum: 8, standard: 2, fewest: 1 } as const;
 
 export interface NewDevice {
   readonly kind: Exclude<NodeKind, 'unsupported'>;