Interface XsdValidationOutcome

True when the failure is an infrastructure finding — the schema failed to load (xsd-schema-load-failed) or the engine itself failed — rather than a document defect. Baseline subtraction against --original must never erase these: they surface as error-severity issues and keep the part invalid under every profile (#289).

Compatibility diagnostics keep their own stable codes, independent of XSD messages.

Structured engine findings for the part, one entry per error occurrence with line when libxml2 reports it. Populated by _validateSingleFileXsd on failure. The strict profile emits these verbatim (deduplicated message strings would collapse repeated identical defects onto one report and lose their locations).

True when the XML sent to the engine differs from the part bytes (template-tag stripping, the markup-compatibility view, or re-serialization). Reported line values then refer to the transformed view, not the source part.

null mirrors Python's (None, None) skip — no schema configured.