ResolvePdfUaEffectiveLanguage function

Resolves the effective natural language of one content position through the ISO 14289 declaration cascade

ResolvePdfUaEffectiveLanguage applies the ISO 14289 language cascade to one content position and fills Resolution with the winning declaration

When HasMarkedContentLanguage is True the marked-content /Lang value wins and Resolution.Source is pulsMarkedContent

Otherwise the element at ElementIndex and its ancestors are walked through ParentIndex until one carries a non-empty Language; Resolution.Source is then pulsStructure and StructureElementIndex records the declaring element

When no structure element declares a language, a non-empty CatalogLanguage applies with Source pulsCatalog

Each candidate is validated with IsPdfUaLanguageTagValid and the outcome is stored in Resolution.DeclarationValid

The function returns Resolution.IsCovered, which is True only when a declaration was found and it is a well-formed tag

When no candidate exists, Resolution keeps Source pulsNone with an empty Language and the result is False

• The ancestor walk is bounded by the element count, so a cyclic ParentIndex chain cannot loop
• TPdf.InspectPdfUaLanguageCoverage uses this resolver for every reported language span
• A well-formed but semantically wrong declaration is still reported as covered, because the check is syntactic

IsPdfUaLanguageTagValid, TPdf.InspectPdfUaLanguageCoverage, TPdf.Language, TPdf.StructureElements