feat(fls): XMLEncoder reader following java.beans.XMLDecoder

A generic interpreter for the .fls configuration: objects, properties,
calls, indexes, static fields and factories, Field.set, and id/idref
anywhere — including getter results, answered from the measured Java
defaults or reported as unresolved. All 23 corpus files: class and
position of every node as Java reads them, also where Swift loses nodes.

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

packages/fls/test/tsconfig.json

@@ -4,7 +4,12 @@
     "noEmit": true,
     "composite": false,
     "declaration": false,
-    "types": ["node"]
+    "types": [
+      "node"
+    ],
+    "resolveJsonModule": true
   },
-  "include": ["."]
+  "include": [
+    "."
+  ]
 }