oakstorage (new workspace member): URI dispatch, pluggable backends
(ove-xml built in, otio/fcpxml via oakotio, C-vtable foreign
registration), the M10 C API surface, version info codes, last-error
and alive accounting; round-trip tests per backend.
oaknode serializer: persists the full timeline — sequence track lists,
track block lists, block ranges/media_in/speed/flags, clip footage
references, footage filename+streams, folder children — through
<custom> behavior hooks with two-phase reference resolution; loads the
C++ <olive><project><layout> containers (golden: tests/
project_with_footage.ove); round-trip is field-by-field and
byte-idempotent.