Refactor tests to use _All_True model types throughout
Replaced all usages of legacy test model types (e.g., TestOrder, TestOrderItem, SharedTag, etc.) with new, feature-complete _All_True variants across SignalR test infrastructure, data sources, and service handlers. Updated all generic constraints, method signatures, and test data to use the new types. Added SharedTestBaseModels.cs and SharedTestOrderModels.cs to define abstract bases and concrete _All_True models with full serialization attributes. This enables more thorough and realistic serialization/deserialization testing and future extensibility.
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.
Extend markerless serialization to Boolean and Enum types in AcBinarySourceGenerator and generated writers. Updated IsMarkerlessType and EmitMarkerlessWrite to handle these types directly. Refactored generated code to write DateTime, int, enum, and decimal properties without type markers or property skip checks. Simplified OnStringInterned debug callback in AcBinarySerializer. These changes reduce serialization overhead and improve performance for supported types.
Refactor source generator to emit per-type IGeneratedBinaryWriter classes for [AcBinarySerializable] types, with auto-registration at startup. Integrate generated writers into AcBinarySerializer for direct, delegate-free property writing, bypassing the runtime property loop when possible. Add registry, bridge methods, and update TypeMetadataWrapper for fast lookup. Expand tests to verify generated writers and round-trip correctness. This enables major serialization performance gains and reduces code size for supported types.