`_rich_print_document` escapes uri, title and metadata, the sibling of
the escaped search-result renderer. The remaining comments and
docstrings that narrated rejected alternatives, consequences or history
now state the current invariant. The Sandbox class docstring names the
held connection close() releases, and wrapped docs paragraphs join to
one line.
Two files of 1,405 and 814 lines become seven: scope resolution, lifecycle,
search, documents, expansion, citations and capabilities. `_config`, `_seed`
and the rest move to `helpers.py`, importable by the sandbox tests that share
them, and the package points VCR back at `tests/cassettes/multi_db/`.
