Implements a fully source-generated scan pass for duplicate/reference tracking in SGen binary serialization. The generator now emits ScanObject and ScanForDuplicates methods for each writer, handling null/depth checks, slot-based ref tracking (by Id or object hash), and recursive property scanning (strings, complex types, collections). String interning and reference tracking are feature-flagged via attributes. The runtime scan path now delegates to generated code when available, eliminating reflection and delegate overhead. Adds slot-based IdentityMap arrays to the serialization context for efficient duplicate detection. Also updates metadata, attributes, and test stubs to support these features.
Loretta
77ea512c1f