fix: edit ops review findings

From the review of 7723711:
- The assembler is locked: a client closed for a full queue is closed
  by the task that was sending, loop(), whose disconnect dropped the
  buffer while async_tcp could be copying into it. A whole message is
  taken out of it, so a disconnect can't free it while it is read.
- loop() expires a message stalled for 10 s, freeing its buffer and
  telling its client, instead of holding it until another client came.
  A binary message is refused before it can touch another's buffer.
- Each edit takes only the fields its route reads; one it would ignore
  is refused by name. linkRemote's rolling code goes in under the
  route's name, so applyModelEdit is unchanged again.
- An edit refused for an id that doesn't exist replies not found
  (edit_result_t::missing). A reply that doesn't fit its buffer goes
  as an internal error, so the op still gets one.
- The TYPE table says what becomes of each op (proto_op_t), which the
  socket switches on. The reply address is one proto_reply_to_t. The
  routes and the ops start and queue an edit the same way
  (newModelEdit, submitModelEdit). The full-list texts and the offered
  remote address rule live in ModelEditor.
- e2e: the sort order test skips a list that it would renumber.

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

src/entryPoints/WebUiRoutes.cpp

@@ -81,25 +81,17 @@ static void onUploadDisconnect() {
 // The reply only says it was accepted; the result reaches every client as a
 // requestResult event carrying the same requestId once loop() has applied it.
 static void queueModelEdit(AsyncWebServerRequest *request, model_edit_type_t type, JsonVariantConst body) {
-  if(!beginModelEdit()) {
-    request->send(503, _encoding_json, F("{\"status\":\"ERROR\",\"desc\":\"Busy, try the change again\"}"));
-    return;
-  }
-  model_edit_t *edit = new (std::nothrow) model_edit_t();
+  bool busy;
+  model_edit_t *edit = newModelEdit(type, busy);
   if(!edit) {
-    cancelModelEdit(nullptr);
-    sendQueueFull(request);
+    if(busy) request->send(503, _encoding_json, F("{\"status\":\"ERROR\",\"desc\":\"Busy, try the change again\"}"));
+    else sendQueueFull(request);
     return;
   }
-  edit->type = type;
   edit->requestId = nextEditRequestId();
   edit->doc.set(body);
   const uint32_t requestId = edit->requestId;
-  loop_item_t item;
-  item.type = loop_item_type_t::model_edit;
-  item.edit = edit;
-  if(edit->doc.overflowed() || !loopQueue.submit(item)) {
-    cancelModelEdit(edit);
+  if(!submitModelEdit(edit)) {
     sendQueueFull(request);
     return;
   }