v0.6.1

• CI: added wasm32 coverage for the core Rust crates (#186), external BMOPF
  JSON Schema validation for emitted distribution documents (#192), and
  generated .pio.json / model JSON schema drift checks (#178).
• Distribution fidelity (#197): OpenDSS and BMOPF writers preserve transformer
  winding voltage bases, no load admittance, tap settings, neutral impedances,
  and multi winding transformer structure. Roundtripped OpenDSS decks now run
  through a solve oracle that checks voltage agreement, load voltage model
  behavior, and neutral return handling.
• Distribution DER mapping (#197): typed IBR and control profile data now round
  trips through OpenDSS PVSystem / Generator / InvControl and BMOPF
  ibr / control_profile records, with warnings for unsupported control
  details.
• .pio.json documents (#181, #193): added the study block for replayable
  balanced model edits, materialization helpers, deterministic uid stamping,
  and balanced reader warnings as structured .pio.json diagnostics.
• Normalization (#188): added an opt-in angle bound clamp pass with Rust, C ABI,
  and Python entry points; existing normalization behavior is unchanged.
• Distribution graph projection (#182): added a bus and terminal graph view for
  DistNetwork, including transformers, open switches, and terminal metadata.
• Matrix bindings (#190): added Arrow C ABI matrix exports as COO triplet tables
  for Ybus, incidence, B', and B'', with C and Python golden coverage.
• Sensitivities (#8): added sparse and iterative PTDF/LODF export paths with
  drop tolerance metadata, while retaining the dense path as the small case
  oracle.
• Documentation (#191): standardized released docs, READMEs, and crate metadata
  around .pio.json document, model JSON, and metadata terminology.
  powerio-py continues to inherit the workspace version; no separate Python
  version bump is needed.

What's Changed

• Add wasm32 CI check by @samtalki in #198
• Preserve transformer neutral impedance by @samtalki in #199
• Add OpenDSS solve fidelity oracle by @samtalki in #200
• Map distribution IBR controls to OpenDSS by @samtalki in #201
• Validate emitted BMOPF JSON in CI by @samtalki in #202
• Clamp normalize angle bounds opt in by @samtalki in #203
• Add package study block diagnostics by @samtalki in #204
• Add distribution graph projection by @samtalki in #205
• Add C ABI matrix Arrow tables by @samtalki in #206
• Sparse PTDF and drop tolerance by @samtalki in #207
• Serve generated JSON Schemas by @samtalki in #208
• Prepare v0.6.1 release by @samtalki in #209

Full Changelog: v0.6.0...v0.6.1