TDD step 9: package-root exports (materialize_bundle, IngestResult, the
typed error hierarchy, manifest types) and the two missing named seam
tests — provenance stamping verified with an independent frontmatter
parser, and navigability verified by resolving every index link. The
test module header maps all six library-side §11 seams to their named
tests; spec integrity stays with commons.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QeqhJpYQyghASjiJo5EhGg
