file_bundle_utils assumes paths are relative to the running process CWD

The file bundle adapters convert relative paths in the OTIO files here:

https://github.com/AcademySoftwareFoundation/OpenTimelineIO/blob/5dff8be58d1c4b63040fc70c8afd261bd31d6e55/src/py-opentimelineio/opentimelineio/adapters/file_bundle_utils.py#L132

This uses the process CWD as the root directory. It might make more sense to make paths relative to the .otio file location. Alternatively, we could disallow relative paths in file bundles entirely.

Start by reading src/py-opentimelineio/opentimelineio/adapters/file_bundle_utils.py around line 132 and compare the two path policies described in the issue. Establish whether relative paths should use the .otio file location or be rejected, then verify that file-bundle path handling consistently follows the selected policy.

Written by the indexing model from the issue text.