Problem
dir_store and src/tiered are gone. WT_STORAGE_SOURCE, add_storage_source / get_storage_source, SWIG StorageSource, and the ENOTSUP stubs in conn_api.c remain.
Change
Delete the public WT_STORAGE_SOURCE type and WT_CONNECTION::add_storage_source / get_storage_source from wiredtiger.h.in, the SWIG StorageSource bindings, and the Method in dist/api_data.py. Delete the ENOTSUP stubs, __wti_conn_remove_storage_source, and the connection storage-source list/lock if they exist only for that API. Run dist/s_all.
Drop unused wiredtiger.StorageSource imports in layered tests (they will not compile once SWIG is gone). Reword table/file tiered_storage= help text that names add_storage_source; do not delete those parse stubs.
Keep WT_FILE_SYSTEM, add_page_log, WT_BUCKET_STORAGE / bstorage / tiered.h / WT_DHANDLE_TYPE_TIERED, connection tiered_storage= parse + error-if-enabled, and objectid.
Test
Ninja Debug + Python. cd dist && ./s_fast. python3 ../test/suite/run.py test_tiered_deprecate test_layered_cursor04 test_layered_schema01. Do not restore old functional test_tiered*.py.