v0.2.0

• PowerWorld .pwb binary reader (#95, #102, #105): read only, covering
  June 2016 through 2022 era exports under header constants 425, 483, 508,
  537, 550, and 551, parity tested against same vintage .aux/.RAW/.m
  siblings up to the 6717 bus Texas7k. Unsupported writer vintages are
  rejected with the format constant named.
• pandapower JSON converter (#106): read and write pandapowerNet JSON.
  Written trafo parameters reproduce the source Y_bus exactly through
  pandapower 3.x's transformer model, ZIP load columns go out in both the
  <= 3.1 and >= 3.2 namings, and CI validates the converter against
  pandapower itself over the vendored fixtures.
• PyPSA CSV folder converter (#106): read and write the static network
  CSV folder, CI validated against PyPSA over the vendored fixtures.
  Folders parse through parse_file(..., "pypsa-csv"), auto-detected for
  a directory holding network.csv; the CLI takes --from pypsa-csv and
  --to pypsa-csv -o <dir>.
• PowerWorld .pwd display reader (#102): substation diagram coordinates,
  matched 1-1 against the aux substations on every probed save with a same
  vintage aux (the v19 resave matches 1248/1250 against the published
  case, a vintage skew).
• Read fidelity channel (#106): parse_file/parse_str return
  Parsed { network, warnings }, so what a reader cannot carry is
  itemized instead of dropped silently. Python exposes
  Network.read_warnings and the MCP tools report it; the C ABI gains
  pio_parse_warnings and pio_write_pypsa_csv_folder (additive, ABI
  version stays 3).
• Full .aux fidelity (#95): all three field naming generations through
  Simulator 21+, validated against the vendored ACTIVSg200 set.
• docs/powerworld.md records the decode evidence, mapping notes, and the
  coverage matrix the corpus tests assert.

What's Changed

• feat(powerworld): full aux fidelity, .pwb reader, ACTIVSg validation by @samtalki in #95
• feat(powerworld): 2019+ era .pwb decode, table search at speed, .pwd substation coordinates by @samtalki in #102
• feat(powerworld): every Texas7k save decodes; the 2021 era record layouts and headers 483 through 551 by @samtalki in #105
• issue-47 by @qian-harvard in #106
• release: 0.2.0 by @samtalki in #108
• fix: rename powerworld/aux.rs, a Windows-reserved filename that broke release checkout by @samtalki in #110

Full Changelog: v0.1.1...v0.2.0