Tree: Reorder... for a component's children

Right-click a component (or the app) with two or more children to move them
up and down; OK applies the new order, which is the order they run in. On a
device the order goes there first via Sox reorder, checked against the
device's children, and the file is left alone if it is refused. Undoable.

Also: device host in editor.properties.

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

live_hooks.py

@@ -155,6 +155,43 @@ def live_rename_component(element, new_name):
         return False
 
 
+# ── Reorder Children ────────────────────────────────────────────
+
+def live_reorder_children(parent_element, ordered_children):
+    """In live mode, sends a Sox reorder to the device. Returns True on success.
+
+    The device takes the order only when it names every child it has, no more and no
+    fewer, so the list is checked against what the device last said before it is sent.
+    """
+    ds = _session()
+    if ds is None:
+        return False
+    parent_id = _comp_id(parent_element)
+    if parent_id is None:
+        _fail(f"'{parent_element.get('name', '?')}' has no component id.")
+        return False
+    child_ids = []
+    for child in ordered_children:
+        cid = _comp_id(child)
+        if cid is None:
+            _fail(f"'{child.get('name', '?')}' has no component id.")
+            return False
+        child_ids.append(cid)
+
+    client = ds.sox_client
+    cached = client.cache_get(parent_id)
+    if cached is not None and set(cached.children) != set(child_ids):
+        _fail("The editor's list of children no longer matches the device's. "
+              "Reconnect to read the device again.")
+        return False
+    try:
+        client.reorder(parent_id, child_ids)
+        return True
+    except Exception as e:
+        _fail(f"The device rejected the reorder: {e}")
+        return False
+
+
 # ── Link / Unlink ───────────────────────────────────────────────
 
 def _link_ends(ds, from_element, from_slot_name, to_element, to_slot_name):