feat(fls): write the topology of a .fls, loaded by Java as the original

topologyWriter.ts writes konfiguration.xml from Java's view of a project:
the version line, the node items (label position, device with name,
host label flags, interfaces or ports), the cable items and the
documentation items. What a device's constructor makes is changed through
getters, as XMLEncoder does, and more is added; fewer than it makes set the
list anew. Cable ends name the port objects the getters return (the writer
now names a getter's result, <void id="Port0" property="port"/>), and each
cable carries the nodes the editor draws it between.

Checked by Java against Java: every corpus file, read and written again,
loads in Java FILIUS (the oracle's loading method, --sha256 ties its result
to the written bytes) to the same devices, names, positions, interfaces,
cables and documentation as the original; so does a synthetic topology with
what the corpus never sets. The oracle and the reader now also report a
cable's drawing ends (JCablePanel ziel1/ziel2): in the corpus the nodes it
joins, for all 183 cables. Mutation probes rewrite the files and let Java
load each mutant.

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

packages/fls/src/topology.ts

@@ -60,6 +60,11 @@ export interface FlsPortReference {
 export interface FlsLink {
   ends: [FlsPortReference, FlsPortReference];
   wireless: boolean;
+  /**
+   * The nodes the editor draws the cable between (JCablePanel ziel1, ziel2),
+   * by index; null where the file names none.
+   */
+  panel: [number | null, number | null];
 }
 
 export type FlsColor = [red: number, green: number, blue: number, alpha: number];
@@ -146,7 +151,10 @@ export function readTopology(values: readonly JavaValue[]): FlsTopology {
   const nodes: FlsNode[] = [];
   for (const [index, item] of nodeItems.entries()) {
     const node = context.node(item, index, nodes.length);
-    if (node !== undefined) nodes.push(node);
+    if (node !== undefined) {
+      if (isJavaObject(item)) context.nodeItems.set(item, nodes.length);
+      nodes.push(node);
+    }
   }
   const links: FlsLink[] = [];
   for (const [index, item] of cableItems.entries()) {
@@ -168,6 +176,8 @@ function listOf(value: JavaValue | undefined, className: string): JavaValue[] {
 class Reader {
   /** Every port object a node owns, to resolve cable ends by identity as Java does. */
   private readonly portOwners = new Map<JavaObject, FlsPortReference>();
+  /** Every node item read, to resolve a cable panel's ends. */
+  readonly nodeItems = new Map<JavaObject, number>();
 
   constructor(private readonly warnings: string[]) {}
 
@@ -310,9 +320,15 @@ class Reader {
       this.warnings.push(`cable ${itemIndex + 1}: an end is not a port of a device, left out`);
       return undefined;
     }
+    const panel = (item as JavaObject).properties.get('kabelpanel');
+    const panelEnd = (property: string) => {
+      const target = isJavaObject(panel) ? panel.properties.get(property) : undefined;
+      return isJavaObject(target) ? (this.nodeItems.get(target) ?? null) : null;
+    };
     return {
       ends: [first, second],
       wireless: this.booleanProperty(cable, 'wireless', `cable ${itemIndex + 1}`),
+      panel: [panelEnd('ziel1'), panelEnd('ziel2')],
     };
   }