CultMesh TS: a node's returned documents belong to its cache

Soul F8 (M6, M7 survived): node.get, getRequired and put return the
object the cache holds, as C# and Python do (Rust copies). That is the
behaviour that ships.

- The README says the returned object belongs to the cache and must not be
  mutated, and shows the put-a-new-value pattern.
- A test pins it: two reads return the same object, put resolves to that
  object, and the caller's own value is never the one held.

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

packages/cultmesh-ts/README.md

@@ -108,6 +108,20 @@ reactive.update(draft => {
 });
 ```
 
+`node.get`, `node.getRequired` and the value `node.put` resolves to return the
+object the node's cache holds, not a copy: two reads of one record return the
+same object. That object belongs to the cache and must not be mutated. Mutating
+it changes what later reads see without writing anything to the store. To
+change a document, build a new value (or use a writer) and put it:
+
+```ts
+const held = station.getRequired(stationStockDocument, "station:starbridge:stock");
+await station.put(stationStockDocument, "station:starbridge:stock", {
+  ...held,
+  availableMissiles: held.availableMissiles - 4,
+});
+```
+
 State pointers are the same kind of managed surface for UI and tools. They can
 advertise source documents, inherit a Verse route when bound, and resolve
 through that Verse without caller-side context plumbing:

packages/cultmesh-ts/test/cultmesh.test.ts

@@ -3074,6 +3074,24 @@ test("CultMesh TS reads remote RUDP snapshots through document handles", async (
   }
 });
 
+// What ships (F8): a node's reads and puts return the object its cache holds, not a copy, and the README says that object
+// belongs to the cache. The caller's own value is never the one held.
+test("CultMesh TS node reads and puts return the cache's own object", async () => {
+  const node = await CultMesh.startNode(
+    join(await mkdtemp(join(tmpdir(), "cultmesh-ts-held-object-")), "node.ccmp"),
+    { documents: [noteDocument] },
+  );
+  const written = { noteId: "note:held", body: "held" };
+  const put = await node.put(noteDocument, "note:held", written);
+  assert.notEqual(put, written);
+  assert.deepEqual(put, written);
+  assert.equal(node.get(noteDocument, "note:held"), put);
+  assert.equal(node.getRequired(noteDocument, "note:held"), put);
+  assert.equal(node.get(noteDocument, "note:held"), node.get(noteDocument, "note:held"));
+  written.body = "changed by the caller";
+  assert.equal(node.getRequired(noteDocument, "note:held").body, "held");
+});
+
 test("CultMesh TS syncs remote RUDP snapshots into a local node", async () => {
   const connectionId = 0x1020304a;
   const source = await CultMesh.startNode(