Analyzes Python source files for docstring quality issues. Runs all
enabled checks except freshness by default (freshness requires git
context; griffe also excluded when not installed). When *path* is a
directory, only files within that directory tree are checked (not the
entire project). Returns a JSON object with findings, summary
statistics, and optional presence coverage data. Invalid
configuration triggers a structured error response instead of
crashing the server.

Args:
    path: Path to a Python file or directory to check.
    checks: Optional list of check names to run. Valid names are
        ``presence``, ``enrichment``, ``freshness``, ``coverage``,
        ``griffe``. Defaults to all except freshness.

Returns:
    JSON string with ``findings``, ``summary``, and optionally
    ``presence_coverage`` keys. Returns an ``error`` key on
    invalid path, unknown check name, or malformed configuration.
    Call docvet_rules() for per-rule fix guidance and format examples.

Returns the complete rule catalog with rule name, associated check
module, human-readable description, category (required or
recommended), prescriptive fix guidance, and a format example.

Returns:
    JSON string with a ``rules`` array containing objects with
    ``name``, ``check``, ``description``, ``category``,
    ``guidance``, and ``fix_example`` keys.