v0.3.3

• MCP server: unified the advertised tool surface to semantic verbs:
  convert, save, summary, parse, normalize, matrix, and display.
  The tools route transmission cases, distribution cases, PyPSA CSV folders, and
  gridfm datasets by format. Distribution parse returns canonical bmopf-json
  as its serial transport; transmission parse returns powerio-json.
  summary now has one canonical JSON schema across MCP and the CLI's new
  powerio summary command. Gridfm is a format behind parse/save, not its
  own MCP tool. PowerWorld .pwd display files parse through display, leaving
  room for a future open display format without renaming the tool. Older case,
  matrix, and PyPSA helper names stay as direct Python compatibility callables
  for one release, but they are no longer advertised as MCP tools.
• Python API: restored the undocumented powerio.Case = Network alias for one
  release, but left it out of __all__ and docs; remove it in 0.4.0. The
  experimental distribution surface now uses powerio.dist.DistNetwork as
  the primary name to match the native DistNetwork hub type, while the
  exported powerio.dist.DistCase = DistNetwork alias stays for one release.
  powerio.dist is gated on the draft BMOPF schema (PIO_DIST_ABI_VERSION = 1)
  and not yet under the stability guarantee.
• No C ABI change: PIO_ABI_VERSION stays 4 and PIO_DIST_ABI_VERSION stays 1,
  and the matrix builders are unchanged. The native extension's internal pyclass
  names changed (PyCase → PyNetwork, _DistCase → _DistNetwork) so repr()
  now renders the public Network(...) / DistNetwork(...) form directly; a
  rebuilt wheel is required.

What's Changed

• MCP: distribution + display tools; unified tool surface by @samtalki in #141

Full Changelog: v0.3.2...v0.3.3