Interpret complete scalar source at the XML owner instead of accepting numeric prefixes, permissive date strings or nonempty booleans. Retain malformed content as explicit unknown scalars with original literals and reasons, while preserving the surrounding archive and independent numeric facts.
Share the representation across plist, keyed archive, Interface Builder and entitlement projection; remove the superseded numeric fallback and helpers. Parse date fields as UTC, retain real entity/CDATA semantics, and distinguish native integer/real whitespace without ambiguous whitespace backtracking.
Validation: 276 source tests and 60 compiled/public tests passed, with updated scalar regressions rerun; static, architecture and docs checks passed. Native macOS plutil controls and CLI/MCP source-hash/time-zone controls executed. No Linux/Windows or deep-provider qualification. Tiny completed CLI task costs recorded; no performance improvement claimed.
BREAKING CHANGE: Unresolved XML scalar values now use $plist_type unknown wrappers with element, literal and reason. This replaces the former real/null unknown marker and malformed scalar prefix fallback. Supported extended UTC years now preserve their timestamp.
Fixes#4852
morluto
3537e58c1a