Modernize benchmarks, simplify attributes, doc cleanup
- Benchmark output now reports per-op µs and KB/op; added helpers for unit conversion and updated all output formats and headers.
- Split SetupAllocBytes into SetupSerializeAllocBytes and SetupDeserializeAllocBytes for finer allocation reporting.
- Simplified [AcBinarySerializable] usage in test models to single-argument form.
- Edited documentation for clarity, brevity, and consistency; improved navigation, updated technical details, and harmonized terminology across .md files.
Refactor docs: topic folders, TOON, XCUT, protocol sync
- Migrated all topic documentation into dedicated folders with canonical `README.md`, `ISSUES.md`, and `TODO.md` per topic (e.g., `LOGGING/`, `SIGNALR/`, `BINARY/`, `TOON/`).
- Added comprehensive TOON serializer documentation: design, format, options, attributes, inference, issues, and TODOs.
- Introduced `XCUT` folder for cross-cutting issues and TODOs, with canonical entries and topic cross-references.
- Updated all references and navigation to use new folder-based doc paths; fixed links and clarified doc structure.
- Enhanced AI agent protocol: enforce session skill preloading, `[LOADED_DOCS: ...]` short-name prefix, and mandatory `docs-check` skill for doc/code sync.
- Updated `.csproj` to include all `README.md` files for IDE visibility.
- Improved and clarified SignalR, grid, and project-level documentation.
- Minor code/test tweaks and doc content corrections for consistency.
Loretta