cultmesh-ts: count and answer a frame that decodes but is no message the parser takes

A map with an unknown schemaVersion was rethrown: unanswered, uncounted toward the
session cap. It is now answered message_invalid, reported, and counted like any other
unreadable frame, so the cap holds for it.

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

packages/cultmesh-ts/src/index.ts

@@ -5678,9 +5678,13 @@ export class CultMesh {
         // A frame the server cannot read is judged as the write it looks like (a put when it does not even decode), so
         // an ungranted peer hears the same refusal for it as for any other write, not a parse error.
         const write = readableWrite(decoded);
-        if (decoded !== undefined && !write) throw error;
         record.unreadableInARow += 1;
-        if (!await writeRefused(record, write?.operation ?? "put", write?.schemaId ?? "", write?.recordKey ?? "", null, null)) {
+        if (decoded !== undefined && !write) {
+          // It decodes but is no message the parser takes (an unknown schemaVersion, a non-map) and is no write the
+          // authority could judge: answered and counted like any other unreadable frame.
+          reportError(error);
+          sendSchemaMessage(record, cultNetMessageInvalidError("message", "CultMesh RUDP document server could not read the message."));
+        } else if (!await writeRefused(record, write?.operation ?? "put", write?.schemaId ?? "", write?.recordKey ?? "", null, null)) {
           reportError(error);
           sendSchemaMessage(record, cultNetMessageInvalidError("message", "CultMesh RUDP document server could not read the write."));
         }

packages/cultmesh-ts/test/remote-write-authority.test.ts

@@ -563,3 +563,30 @@ test("deletes the authority refuses are answered and the session kept until eigh
     assert.equal(r.deletes.length, 1);
   });
 });
+
+test("a frame that decodes but is no message the parser takes is answered, counted, and ended at eight in a row like any unreadable frame", async () => {
+  const r = await rawRig(new Recording(grant));
+  const unknown = () => encodeWireValue({ schemaVersion: "cultnet.not-a-message.v0", messageId: "x" });
+  try {
+    const batch = async (frames: number) => {
+      for (let i = 0; i < frames; i++) r.send(unknown());
+      await sleep(400);
+    };
+    await batch(CAP - 1);
+    assert.equal(r.replies.length, CAP - 1, "each is answered");
+    assert.equal(r.errors.length, CAP - 1, "and reported");
+    r.send(encodeWireValue(put(KEY_A)));
+    await sleep(250);
+    assert.deepEqual(r.puts.map((p) => p.recordKey), [KEY_A], "the session was kept through seven");
+    await batch(CAP - 1);
+    assert.equal(r.replies.length, 2 * (CAP - 1), "the decoded put reset the run");
+    r.send(unknown());
+    await sleep(300);
+    assert.equal(r.replies.length, 2 * (CAP - 1) + 1, "the eighth is answered too");
+    for (const reply of r.replies) {
+      assert.equal((reply as { code?: string }).code, "message_invalid");
+      assert.equal((reply as { details: { field: string } }).details.field, "message");
+    }
+    assert.throws(() => r.send(unknown()), /before the session is connected/, "then the session ended");
+  } finally { r.close(); }
+});