goldenmatch v3.10.0

Added

• 3 host-helper MCP tools (server_info, read_file, write_csv) -- the last
  ts_only entries. mcp_tools.ts_only is now EMPTY: the TS MCP surface is a
  strict subset of the Python one (83 shared, 0 TS-only, 7 Python-only). goldenmatch
  MCP tools 87 -> 90. server_info.tool_count is DERIVED from the live tool list,
  never a literal, so it cannot drift from the real surface.

Security note (behavior unchanged, now documented + tested)

• read_file / write_csv route through the same core._paths.safe_path guard every
  other file-taking tool uses. That guard rejects NUL bytes and resolves the path, but
  enforces containment only when GOLDENMATCH_ALLOWED_ROOT is set. With it unset
  (the default) these tools reach anything the server process can -- identical to the
  pre-existing upload_dataset / export_results, so this adds no new reach. Both
  modes are now pinned by tests, and the contract is stated on the API-surface page.
  write_csv additionally refuses anything that is not a list of objects.