v0.5.0

This release reshapes the configuration and reporting surface across Rust, Python, and JavaScript so the three APIs share one configuration tree and one set of override semantics. Transform reports become opt-in, TransformConfig is organized by phase, serialization options are flattened, and binding exception categories are corrected. It also hardens parser recovery and diagnostics, fixes serialization of bare delimiter arguments, and adds two corpus rules. Most changes are breaking; see Changed for migration notes.

Added

• normalize_with_report / transform_with_report on the Rust facade and the Python binding (normalizeWithReport / transformWithReport in JavaScript) for callers that need the diagnostic report. Report types now live in texform::diagnostics.
• Effective defaults are exposed on every binding: default_parse_config() / default_transform_config() in Python and defaultParseConfig() / defaultTransformConfig() in JavaScript return the engine's profile defaults. Rust adds TransformEngine::default_normalize_config().
• RewriteConfig, plus the serialization option enums (CommandSpacing, MathGroupInnerSpacing, AdjacentCharSpacing, ScriptSpacing, ScriptOrder, InfixGrouping, EnvironmentNameSpacing), are re-exported from the Rust facade.
• Corpus rules leftroot-drop and uproot-drop drop the AMS \leftroot / \uproot index-position hints.

Changed

• Breaking: transform reports are opt-in. normalize / normalize_with now return the canonical string and transform / transform_with return nothing, in Rust, Python, and JavaScript, so plain calls no longer pay for report collection or host-object conversion. NormalizeResult and the FinalizeAstStep* types are removed. The report itself is restructured (rewrite.{iterations, rules}, flattened FinalizeAst counters, flatten_groups.guard_hits with short guard names) and remains a diagnostic rather than a stability promise.
• Breaking: TransformConfig is organized by phase. The flat rewrite_enabled, lower_attributes_enabled, and max_iterations fields become rewrite: RewriteConfig { enabled, max_iterations } and lower_attributes: LowerAttributesConfig, alongside the existing finalize_ast and flatten_groups. Profile defaults are unchanged.
• Breaking: FlattenGroupsConfig exposes only enabled and preserve_rendered_spacing (preserveRenderedSpacing in JavaScript). The eleven preserve_* guard fields are removed and old keys are rejected.
• Breaking: serialization options are a flat set of seven fields; the nested math / syntax shape is removed. Python takes snake_case keyword arguments (doc.to_latex(script_order="sup_first"), serialize(node, **options)), and JavaScript takes a flat camelCase object.
• Breaking: configuration inputs are unified across bindings. Python reserves config= for a complete config object (TransformConfig, ParseConfig); partial settings are passed as keyword overrides that keep unspecified defaults, and a dict passed as config is rejected. JavaScript accepts the same nested override tree in normalize and transform, with omitted fields keeping the profile default. Unknown keys and wrongly typed values raise ConfigError / TexformConfigError with the field path. The unused WASM config classes and parseWith are removed.
• Breaking: binding exception categories are corrected. Python cross-document edits raise EditError instead of ParseError. Transforming a document that has parse errors raises TransformError in Python and TexformTransformError (kind: "transform") in JavaScript instead of the internal kind. The undocumented Complete<T> type is no longer importable from the npm typings.

Fixed

• Parser recovery under reject_unknown without abort_on_error consumes only the unknown command, so \mycmd{x} + y yields a partial document instead of failing the whole parse. A stray } is no longer reported as an environment-name mismatch, and ^ / _ with missing content report Missing superscript content / Missing subscript content.
• Diagnostics keep their structured kind and precise source span through nested content parsing instead of highlighting the outer command or closing brace, and internal kind labels no longer leak into messages.
• Literal carriage returns are treated as whitespace, so Windows (CRLF) and CR-only inputs parse instead of panicking.
• Mandatory delimiter arguments are serialized without braces (\middle \vert, \big \langle, \genfrac . . {} {}), so the output renders in MathJax again.
• JavaScript: normalize with a flattenGroups override now layers it on the engine profile's defaults instead of the strict baseline.
• JavaScript: internal DTO serialization failures are thrown as TexformError (kind internal) instead of being returned as successful values.
• Python: invalid per-call config objects raise ConfigError consistently across parse, normalize, and transform.