v0.3.0

Added

• Native-toolchain formatter backends — opt-in backends that invoke a
  language's canonical first-party CLI when it is present on the host: Java,
  Kotlin, R, Swift, Dart, and Gleam. Off by default (enabled per-tool in config);
  when the tool is absent the language falls through to the tier-2 tree-sitter
  formatter, so the zero-dependency guarantee is intact for anyone who has not
  opted in.
• C# tier-2 support — a Language::CSharp variant so .cs files route to the
  tree-sitter generic formatter (deterministic, zero system dependency) instead of
  being skipped. Maps the c# / csharp catalog names and the .cs extension.
• Elixir do…end reindent in the tier-2 formatter. Elixir's blocks are
  keyword-delimited (do…end), so they matched neither the brace-counting path nor
  a language-pack indents query (tree-sitter-elixir ships none) and were left at
  column 0. A new built-in-indents-query dispatch slot plus a minimal Elixir query
  produces mix format's 2-space nesting; idempotent, with heredocs/strings
  preserved.

Changed

• poly fmt honors // swift-format-ignore-file — a Swift file carrying the
  directive is left byte-for-byte untouched (the same whole-file skip marker
  swift-format respects), mirroring the generated-lock-file skip. Protects files a
  project opted out of formatting and machine-generated swift-bridge glue.
• Bumped fs-err, serde-saphyr, and sqruff to their latest releases.

Fixed

• poly hooks now enforces the commit-msg stage. Lowered hooks kept
  Stage::default() (pre-commit), so the runner dispatched the poly commit
  (Conventional Commits) builtin in file-input mode, matched no files, and silently
  skipped it — the git commit-msg hook never enforced anything. Every lowered hook
  is now stamped with the stage it was lowered for; latent for any non-pre-commit
  builtin, only poly-commit surfaced it.
• Rust files named like dockerfile.rs are no longer misdetected as
  Dockerfiles. Language detection now lets a known file extension (.rs → Rust)
  win over the Dockerfile filename match, so engines/dockerfile.rs and similar no
  longer produce spurious Dockerfile parse errors.