Crashes when Clip parent is null

An LLM-based code review claims that there are some bugs related to orphaned clips (Clip instances with a null parent).

> item.cpp:87-109 — range_in_parent/trimmed_range_in_parent on an orphan clip set the error then still call parent()->... on null. Same pattern in transition.cpp:58-90.
> composition.cpp:254-273 — _path_from_child walks current->parent() off the end for orphan/foreign children: track->range_of_child(orphan) crashes.

Could we get a volunteer to verify if this is a real bug? It sounds plausible, and could be easily verified by writing a test case and/or a test OTIO file that creates the scenario described.

Start by inspecting item.cpp:87-109, transition.cpp:58-90, and composition.cpp:254-273, then look for the existing tests covering orphaned or foreign clips. Create a test case or test OTIO file for null-parent clips and track range lookup. Done means each reported scenario is verified with a regression test or shown not to reproduce.

Written by the indexing model from the issue text.